Acinetobacter

Infect Immun, 2000 Jun, 68(6), 3657 - 66
An OmpA-like protein from Acinetobacter spp . stimulates gastrin and interleukin-8 promoters; Ofori-Darko E et al.; Bacterial overgrowth in the stomach may occur under conditions of diminished or absent acid secretion . Under these conditions, secretion of the hormone gastrin is elevated . Alternatively, bacterial factors may directly stimulate gastrin . Consistent with this hypothesis, we found that mice colonized for 2 months with a mixed bacterial culture of opportunistic pathogens showed an increase in serum gastrin . To examine regulation of gene expression by bacterial proteins, stable transformants of AGS cells expressing gastrin or interleukin-8 (IL-8) promoters were cocultured with live organisms . Both whole-cell sonicates and a heat-stable fraction were also coincubated with the cells . A level of 10(8) organisms per ml stimulated both the gastrin and IL-8 promoters . Heat-stable proteins prepared from these bacterial sonicates stimulated the promoter significantly more than the live organism or unheated sonicates . A 38-kDa heat-stable protein stimulating the gastrin and IL-8 promoters was cloned and found to be an OmpA-related protein . Immunoblotting using antibody to the OmpA-like protein identified an Acinetobacter sp . as the bacterial species that expressed this protein and colonized the mouse stomach . Moreover, reintubation of mice with a pure culture of the Acinetobacter sp . caused gastritis . We conclude that bacterial colonization of the stomach may increase serum gastrin levels in part through the ability of the bacteria to produce OmpA-like proteins that directly stimulate gastrin and IL-8 gene expression . These results implicate OmpA-secreting bacteria in the activation of gastrin gene expression and raise the possibility that a variety of organisms may contribute to the increase in serum gastrin and subsequent epithelial cell proliferation in the hypochlorhydric stomach.

Epidemiol Infect, 2000 Apr, 124(2), 233 - 7
The stethoscope in the Emergency Department: a vector of infection?
Nunez S, Moreno A, Green K, Villar J.
The purposes of this study were to determine whether microorganisms can be isolated from the membranes of stethoscopes used by clinicians and nurses, and to analyse whether or not the degree of bacterial colonization could be reduced with different cleaning methods . We designed a transversal before-after study in which 122 stethoscopes were examined . Coagulase negative staphylococci (which are also potentially pathogenic microorganisms) were isolated together with 13 other potentially pathogenic microorganisms, including S . aureus, Acinetobacter sp . and Enterobacter agglomerans . The most effective antiseptic was propyl alcohol . Analysis of the cleaning habits of the Emergency Department (ED) staff, showed that 45% cleaned the stethoscope annually or never . The isolation of potentially pathogenic microorganisms suggests that the stethoscope must be considered as a potential vector of infection not only in the ED but also in other hospital wards and out-patient clinics.

J Med Assoc Thai, 2000 Apr, 83(4), 392 - 7
Nosocomial pneumonia in a newborn intensive care unit; Petdachai W; Nosocomial pneumonia is a major cause of morbidity and mortality in hospitalized patients . The risk is especially high in the neonatal intensive care unit (NICU) particularly in infants with mechanically assisted ventilation . During the 5-year period of the study, 160 infants with problems including prematurity (60.6%), respiratory distress (55.6%) and birth asphyxia (45.0%) were admitted to the NICU . One hundred and thirty-three infants (83.1%) received mechanical ventilation . Nosocomial pneumonia was found in 65 infants (40.6%) or 88.3 cases per 1,000 ventilator-days . Low birth weight, prematurity, respiratory distress and hyperbilirubinemia were found more significantly in the pneumonia group . They underwent more manipulations such as the placement of an umbilical catheter and orogastric tube . Infants with pneumonia received mechanical ventilation at a higher percentage and for a longer period than those without pneumonia (96.9% vs 73.7%, odds ratio = 11.2, p = 0.000) with a mean duration of 11.7 and 3.5 days respectively (p = 0.000) . The etiologic organisms recovered from hemoculture were Acinetobacter calcoaceticus var . anitratus 44.0 per cent, Enterobacter spp . 16.0 per cent, Klebsiella pneumoniae 16.0 per cent, coagulase-negative staphylococci 12.0 per cent . There was no concordance of the bacteriologic results in endotracheal aspirate culture and hemoculture in each infant . Leukocytosis and granulocytosis as well as blood gas values could not differentiate the presence of pneumonia . The mean hospital stay for the infants with pneumonia was longer (23.0 days vs 6.4 days, p = 0.000) . Nosocomial pneumonia did not only prolong hospital stay but also contributed to mortality . Twenty-seven (41.5%) of the infants with pneumonia died, compared with 46 (48.4%) of the other group without pneumonia (p = 0.422) . The risk of nosocomial pneumonia can be reduced by using infection control measures, including meticulous hand washing and gloving during respiratory manipulation, heat-treated water supply in a nebulizing unit of the ventilator and proper care of umbilical catheterization.

Med Dosw Mikrobiol, 1999, 51(3-4), 221 - 32
{Studies on siderophore exchange properties between staphylococci and various species of gram-positive and gram-negative bacteria}; Szarapinska-Kwaszewska J et al.; The ability of iron utilizing by means of staphylococcal siderophores by bacteria belonging to genera: Acinetobacter, Corynebacterium, Curtobacterium, Clavibacter, Bacillus and Mycobacterium was investigated . The staphylococcal donor strains (18 species) used in these experiments were characterized by the ability to utilize siderophores produced by various strains belonging to aforenamed genera . The utilization of staphylococcal siderophores was studied on agar media in which minimally effective concentrations of ethylenediaminedi-ortho-hydroxyphenylacetic acid (EDDA) were used to inhibit indicator strains . Test colonies (staphylococcal) were applied to the surface of the media to determine whether the indicator organisms could obtain the required iron for growth by utilizing chelators from the test colony . The growth inhibition by EDDA of most strains from the Acinetobacter rods and from the coryneform-organisms (plant pathogen) genera, and strains from the species: B . subtilis, M . phlei, M . smegmatis, M . fortuitum was reversed by staphylococcal siderophores . None of the staphylococcal strains investigated, had the ability to exchange siderophores with strains from the species: C . pseudodiphtheriticum, Corynebacterium ANF group, B . megaterium, M . vaccae, M . chitae and M . parafortuitum.

Am J Surg, 2000 Feb, 179(2A Suppl), 2S - 7S
Importance, morbidity, and mortality of pneumonia in the surgical intensive care unit; Barie PS; Surgical patients are at high risk to develop nosocomial pneumonia, although an accurate diagnosis is difficult to make . Staphylococcus aureus and Pseudomonas aeruginosa are the most common pathogens, but Acinetobacteris emerging as an important pathogen . Because affected patients are often critically ill with multisystem pathology, it can be difficult to ascribe morbidity or mortality directly to the infection.

Structure Fold Des, 2000 Apr 15, 8(4), 429 - 40
The 1.8 A crystal structure of catechol 1,2-dioxygenase reveals a novel hydrophobic helical zipper as a subunit linker; Vetting MW et al.; BACKGROUND: Intradiol dioxygenases catalyze the critical ring-cleavage step in the conversion of catecholate derivatives to citric acid cycle intermediates . Catechol 1,2-dioxygenases (1, 2-CTDs) have a rudimentary design structure - a homodimer with one catalytic non-heme ferric ion per monomer, that is (alphaFe(3+))(2) . This is in contrast to the archetypical intradiol dioxygenase protocatechuate 3,4-dioxygenase (3,4-PCD), which forms more diverse oligomers, such as (alphabetaFe(3+))(2-12) . RESULTS: The crystal structure of 1,2-CTD from Acinetobacter sp . ADP1 (Ac 1,2-CTD) was solved by single isomorphous replacement and refined to 2.0 A resolution . The structures of the enzyme complexed with catechol and 4-methylcatechol were also determined at resolutions of 1.9 A and 1.8 A, respectively . While the characteristics of the iron ligands are similar, Ac 1,2-CTD differs from 3,4-PCDs in that only one subunit is used to fashion each active-site cavity . In addition, a novel 'helical zipper', consisting of five N-terminal helices from each subunit, forms the molecular dimer axis . Two phospholipids were unexpectedly found to bind within an 8 x 35 A hydrophobic tunnel along this axis . CONCLUSIONS: The helical zipper domain of Ac 1, 2-CTD has no equivalent in other proteins of known structure . Sequence analysis suggests the domain is a common motif in all members of the 1,2-CTD family . Complexes with catechol and 4-methylcatechol are the highest resolution complex structures to date of an intradiol dioxygenase . Furthermore, they confirm several observations seen in 3,4-PCDs, including ligand displacement upon binding exogenous ligands . The structures presented here are the first of a new family of intradiol dioxygenases.

Arzneimittelforschung, 2000 Apr, 50(4), 387 - 90
Effect of meropenem on the vascular permeability factor produced by Acinetobacter baumannii; Hostacka A; Eleven Acinetobacter baumannii strains produced a toxic substance--the vascular permeability factor--in the culture medium . Intradermal injection of this substance enhanced vascular permeability in the rabbit skin . The extent of permeability reactions varied from 0.28 cm2 to 1.61 cm2 . Changes in the permeability factor activity of four A . baumannii strains after treatment with meropenem (CAS 96036-03-2) at suprainhibitory concentrations (2x, 4x or 8x) minimum inhibitory concentration (MIC) or supra-subinhibitory ones (2-8x MIC + 0.2x MIC) were tested in vitro . Meropenem at all suprainhibitory concentrations (with the exception of 8x MIC for one strain) was almost ineffective . Alterations in this activity were in the range of 93% to 106% of the control values . Supra-subinhibitory concentrations of meropenem significantly increased the permeability factor activity (to 150%-176% of the control values) . These findings indicate that meropenem mainly at supra-subinhibitory concentrations can in vitro interfere with the vascular permeability factor produced by A . baumannii.

Braz J Infect Dis, 2000 Apr, 4(2), 91 - 9
Antimicrobial resistance in Brazil: comparison of results from two multicenter studies; Sader HS; To evaluate whether our previous study of the antimicrobial resistance patterns in three centers in Brazil represented the pattern in the country as a whole, the results were compared to new data on 855 isolates from 20 clinical laboratories and 36 hospitals located in different regions of Brazil . Both multicenter studies showed high rates of antimicrobial resistance among Gram-negative bacilli isolated in Brazilian hospitals with the most important problems being: 1) E.coli and K.pneumoniae that produce ESBL; 2) Enterobacter spp . which likely express chromosomally mediated (AmpC) stably derepressed cephalosporinases producing resistance to third-generation cephalosporins and broad spectrum penicillins; 3) carbapenem resistance among Acinetobacter spp . and P.aeruginosa; and 4) fluoroquinolone and aminoglycoside resistance among many Gram-negative species . Our results emphasize the importance of regional antimicrobial resistance surveillance programs in guiding empirical therapy and for focusing intervention controls of antimicrobial resistance . Although the SENTRY Program has only three participating centers in Brazil, its results were validated by a larger Brazilian multicenter study.

Diagn Microbiol Infect Dis, 2000 May, 37(1), 63 - 74
Frequency of occurrence and antimicrobial susceptibility patterns for pathogens isolated from latin american patients with a diagnosis of pneumonia: results from the SENTRY antimicrobial surveillance program (1998); Lewis MT et al.; The correct empiric choice of antimicrobial therapy in the treatment of pneumonia in hospitalized patients has established itself as a major therapeutic challenge to clinicians . Selection of an inappropriate antimicrobial agent could lead to increased rates of mortality and morbidity . Characteristics of pathogens responsible for this infection such as species prevalence, overall antimicrobial resistance rates, and mechanisms of detected resistance could serve as an invaluable resource to clinicians in making such therapeutic selections . This report addresses the aforementioned problems/needs by analysis of 712 strains isolated from the lower respiratory tract of patients hospitalized with a diagnosis of pneumonia in 10 Latin American medical centers in the SENTRY Antimicrobial Surveillance Program (1998) . The four most frequently isolated pathogens (no/% of total) were: Pseudomonas aeruginosa (191/26.8%), Staphylococcus aureus (171/24.0%), Klebsiella spp . (86/12.1%), and Acinetobacter spp . (75/10.5%); representing nearly 75.0% of all isolates . More than 40 antimicrobial agents (23 reported) were tested against these isolates by reference broth microdilution methodology, and susceptibility profiles were established . The nonfermentative Gram-negative bacteria (P . aeruginosa and Acinetobacter spp.) exhibited high levels of resistance to the agents tested . Amikacin (77.5% susceptible) was the most active drug tested against P . aeruginosa 50.0% against the Acinetobacter spp . isolates . Based on published interpretive criteria, over 22.0% of the Klebsiella spp . and 12.5% of the Escherichia coli were classified as extended spectrum beta-lactamase (ESBL) producers . Of the cephalosporin class compounds tested against the Klebsiella spp . and E . coli isolates, cefepime demonstrated the highest rates of susceptibility (84.9% and 91.7%, respectively) . This compound also fared well against the Enterobacter spp . isolates, inhibiting 88.2% of the isolates tested, many of which were resistant to ceftazidime and ceftriaxone . Resistance to oxacillin among the S . aureus isolates was nearly 50 . 0%, with vancomycin, teicoplanin, and the streptogramin combination quinupristin/dalfopristin inhibiting all isolates . Several clusters of multiply resistant organisms were also observed, and further characterization by ribotyping and pulsed-field gel electrophoresis established possible patient-to-patient spread . The results of this study indicate that rates of resistance among respiratory tract pathogens continue to rise in Latin America, with specific concerns for the high prevalence of nonfermentative Gram-negative bacteria isolated, oxacillin resistance rates in S . aureus, and the epidemic dissemination of multiply-resistant strains in several medical centers . International surveillance programs (SENTRY) should assist in the control of escalating antimicrobial resistance in this geographic area.

J Appl Microbiol, 2000 Apr, 88(4), 711 - 9
Use of the MIDI-FAME technique to characterize groundwater communities; Glucksman AM et al.; Fatty acid methyl ester (FAME) profiles were identified directly from groundwater microbial communities concentrated on and extracted with polycarbonate filters . The sensitivity of this direct extraction method was determined using pure cultures of Acinetobacter junii, Pseudomonas putida and Stenotrophomonas maltophilia . A minimum concentration of 107 cells filter-1 was required to identify the predominant fatty acids from each culture . However, at least 3.7 x 109 cells filter-1 were required to obtain fatty acid profiles that matched the signature profiles for pure cultures in a commercial database . While several saturated fatty acids (i.e . 14 : 0, 16 : 0, 18 : 0) were extracted from the polycarbonate filters, they were readily subtracted from microbial fatty acid profiles and did not interfere with the characterization of pure cultures or environmental samples . For the environmental samples, 3 l of groundwater from the Savannah River Site, Aiken, SC, (USA) contained sufficient biomass for direct extraction . A comparative analysis of FAME groundwater profiles demonstrated a qualitative difference among communities sampled from spatially discrete locations, while a groundwater well that was sampled at two time points showed strong similarities over time . Concentration of microbial biomass on polycarbonate filters coupled with the MIDI-FAME extraction of both biomass and filter was a useful technique to characterize microbial communities from groundwater.

Braz J Infect Dis, 2000 Feb, 4(1), 22 - 8
Comparative evaluation of the in vitro activity of three combinations of beta-lactams with beta-lactamase inhibitors: piperacillin/tazobactam, ticarcillin/clavulanic acid and ampicillin/sulbactam; Sader HS et al.; Recently, two new combinations of Beta-lactam antibiotics with Beta-lactamase inhibitors became commercially available in Brazil: piperacillin/tazobactam and ampicillin/sulbactam . This study was designed to assess and compare the in-vitro activity of these new compounds, as well as that of ticarcillin/clavulanic acid, against bacteria isolated in our environment . A total of 749 bacteria isolated at Sao Paulo Hospital were tested using the disk diffusion method, in compliance with NCCLS standardization, using strict quality control . Only one sample per patient was included in the study . Oxacillin-resistant staphylococcus samples were not included in this study . Of the total samples tested, 84.5% were susceptible to piperacillin/tazobactam, 81.2% to ticarcillin/clavulanic acid, and 77.6% to ampicillin/sulbactam . Piperacillin/tazobactam was also found to be the most active combination of the three against Enterobacteriaceae ( n = 312), inhibiting 91.7% of the bacteria tested . Ticarcillin/clavulanic acid was active against 85.8% of the Enterobacteriaceae, while ampicillin/sulbactam inhibited 83.2% of the samples . This order of the spectrum of action (piperacillin/tazobactam > ticarcillin/clavulanic acid >ampicillin/sulbactam )was maintained for the majority of Enterobacteriaceae species analyzed . Pseudomonas aeruginosa ( n = 117) showed extremely high resistance to the three combinations . Piperacillin/tazobactam was active against 61.5% of the samples, while ticarcillin/clavulanic acid was active against 56.4% of the samples of this species . The activity of ampicillin/sulbactam against P . aeruginosa was extremely low; however, this was the most active combination against Acinetobacter baumannii ( 87.0% susceptibility) . Piperacillin/tazobactam was the most active combination against Stenotrophomonas (Xanthomonas )maltophilia (100% susceptibility) and Burkholderia cepacia (90.9% susceptibility) . The three combinations showed excellent activity against the Gram-positive cocci tested (97.3% to 98.2% susceptibility) . In sum, piperacillin/tazobactam was more active against all Gram-negative species than the other two combinations, with the exception of A . baumannii, and showed similar activity against Gram-positive cocci.

Appl Environ Microbiol, 2000 May, 66(5), 2045 - 51
In vitro ATP regeneration from polyphosphate and AMP by polyphosphate:AMP phosphotransferase and adenylate kinase from Acinetobacter johnsonii 210A; Resnick SM et al.; In vitro enzyme-based ATP regeneration systems are important for improving yields of ATP-dependent enzymatic reactions for preparative organic synthesis and biocatalysis . Several enzymatic ATP regeneration systems have been described but have some disadvantages . We report here on the use of polyphosphate:AMP phosphotransferase (PPT) from Acinetobacter johnsonii strain 210A in an ATP regeneration system based on the use of polyphosphate (polyP) and AMP as substrates . We have examined the substrate specificity of PPT and demonstrated ATP regeneration from AMP and polyP using firefly luciferase and hexokinase as model ATP-requiring enzymes . PPT catalyzes the reaction polyP(n) + AMP --> ADP + polyP(n-1) . The ADP can be converted to ATP by adenylate kinase (AdK) . Substrate specificity with nucleoside and 2'-deoxynucleoside monophosphates was examined using partially purified PPT by measuring the formation of nucleoside diphosphates with high-pressure liquid chromatography . AMP and 2'-dAMP were efficiently phosphorylated to ADP and 2'-dADP, respectively . GMP, UMP, CMP, and IMP were not converted to the corresponding diphosphates at significant rates . Sufficient AdK and PPT activity in A . johnsonii 210A cell extract allowed demonstration of polyP-dependent ATP regeneration using a firefly luciferase-based ATP assay . Bioluminescence from the luciferase reaction, which normally decays very rapidly, was sustained in the presence of A . johnsonii 210A cell extract, MgCl(2), polyP(n=35), and AMP . Similar reaction mixtures containing strain 210A cell extract or partially purified PPT, polyP, AMP, glucose, and hexokinase formed glucose 6-phosphate . The results indicate that PPT from A . johnsonii is specific for AMP and 2'-dAMP and catalyzes a key reaction in the cell-free regeneration of ATP from AMP and polyP . The PPT/AdK system provides an alternative to existing enzymatic ATP regeneration systems in which phosphoenolpyruvate and acetylphosphate serve as phosphoryl donors and has the advantage that AMP and polyP are stabile, inexpensive substrates.

Prog Urol, 2000 Feb, 10(1), 89 - 91
{Emphysematous pyelonephritis in lithiasic kidney caused by acinetobacter}; Benchekroun A et al.; Emphysematous pyelonephritis is rare . It is exceptionally associated with urolithiasis with obstruction of the collecting system . It is generally observed in female diabetic patients . It is caused by gas-producing bacteria . We report a case in which emphysematous pyelonephritis was caused by an acinetobacter, associated with pelvic ureteral junction lithiasis . Drainage and nephrectomy were necessary to overcome this life threatening situation.

J Vet Med B Infect Dis Vet Public Health, 2000 Feb, 47(1), 37 - 46
Airborne gram-negative bacterial flora in animal houses; Zucker BA et al.; The concentration and the species composition of airborne gram-negative bacteria were studied in four cattle houses, one pig house and one poultry barn . On average only between 0.02 and 5.2% of the total number of culturable aerobic bacteria were identified as gram-negative bacteria . Obligate anaerobic gram-negative bacteria were not isolated at all . In the airborne gram-negative bacterial flora the following bacterial families dominated: the Enterobacteriaceae, the Pseudomonadaceae and the Neisseriaceae . Within the family of the Enterobacteriaceae the species Escherichia coli and Enterobacter agglomerans were predominant . In animal houses using straw as bedding material Ent . agglomerans was most frequent, whereas in animal houses without litter E . coli was mainly found . Airborne Neisseriaceae were isolated very frequently in cow barns with Acinetobacter lowffii as the primary species . Airborne Pseudomonadaceae were found in high concentrations during periods of high air humidity . The results presented may also give some indications on the origin and sources of airborne endotoxins in animal housing.

J Assoc Physicians India, 1999 Oct, 47(10), 1020 - 1
Acinetobacter meningitis following head trauma; Venkataraman S et al.; A case of acinetobacter meningitis following head injury in a patient who developed cerebrospinal fluid otorrhea, and did not have any neurosurgical procedure, is presented . Previously reported cases are cited, with a review of the literature . Pefloxacin monotherapy is associated with a poor clinical response.

J Hosp Infect, 2000 Apr, 44(4), 254 - 60
Use of RAPD-ALF analysis for investigating the frequency of bacterial cross-transmission in an adult intensive care unit; Webster CA et al.; Bacterial cross-transmission was investigated during a 12-month period in an adult intensive care unit (ICU) by the generation of random amplified polymorphic DNA (RAPD) fingerprinting profiles, combined with automated laser fluorescence (ALF) analysis . The potential episodes of cross-transmission identified, were compared with those detected by the conventional first-line screen of antibiogram typing . Over the year, 215 primary gram-negative bacterial isolates were obtained from 160 patients . In total, 22 possible episodes of cross-transmission, involving 70 (44%) of the 160 patients, were identified by RAPD-ALF analysis, and 19 of these were substantiated with epidemiological evidence . Conversely, 31 possible episodes were identified on the basis of antibiogram data, but only three of these episodes, two involving Acinetobacter baumannii and one involving Serratia marcescens, correlated with those identified by RAPD-ALF analysis . It was concluded that analysis of antibiogram data alone is an unreliable method for assessing bacterial cross-transmission, unless the organism involved has a particularly stable or unusual resistance pattern . In contrast, the technique of RAPD-ALF analysis may provide a rapid and simple technique for obtaining an insight into the population dynamics of gram-negative bacteria in adult ICUs .

J Vet Intern Med, 2000 Mar-Apr, 14(2), 177 - 83
The role of Acinetobacter baumannii as a nosocomial pathogen for dogs and cats in an intensive care unit; Francey T et al.; Acinetobacter baumannii is a nosocomial pathogen associated with high morbidity and mortality in humans . Whereas infections with strains of Acinetobacter species have been reported in various situations, the importance of A baumannii as a nosocomial pathogen in veterinary hospitals has not been studied so far . In this retrospective case series, we describe 17 dogs and 2 cats from which A baumannii had been isolated during a 2 1/2-year period . In 7 dogs, A baumannii induced systemic signs of illness, whereas 12 animals showed signs of local infection . In all animals with systemic infection, and in 2 with localized infection, A baumannii contributed to the death of the animal or contributed to euthanasia; the remaining 8 dogs and both cats recovered . Molecular typing of the isolates with restriction polymorphisms of ribosomal DNA provided evidence of nosocomial spread of this pathogen and for the presence of several strains of A baumannii in the hospital environment.

Antimicrob Agents Chemother, 2000 May, 44(5), 1229 - 35
Characterization of the metallo-beta-lactamase determinant of Acinetobacter baumannii AC-54/97 reveals the existence of bla(IMP) allelic variants carried by gene cassettes of different phylogeny; Riccio ML et al.; The metallo-beta-lactamase determinant of Acinetobacter baumannii AC-54/97, a clinical isolate from Italy that was previously shown to produce an enzyme related to IMP-1, was isolated by means of a PCR methodology which targets amplification of gene cassette arrays inserted into class 1 integrons . Sequencing revealed that this determinant was an allelic variant (named bla(IMP-2)) of bla(IMP) found in Japanese isolates and that it was divergent from the latter by 12% of its nucleotide sequence, which evidently had been acquired independently . Similar to bla(IMP), bla(IMP-2) was also carried by an integron-borne gene cassette . However, the 59-base element of the bla(IMP-2) cassette was unrelated to those of the bla(IMP) cassettes found in Japanese isolates, indicating a different phylogeny for the gene cassettes carrying the two allelic variants . Expression of the integron-borne bla(IMP-2) gene in Escherichia coli resulted in a significant decrease in susceptibility to a broad array of beta-lactams (ampicillin, carbenicillin, cephalothin, cefoxitin, ceftazidime, cefepime, and carbapenems) . The IMP-2 enzyme was purified from an Escherichia coli strain carrying the cloned determinant, and kinetic parameters were determined with several beta-lactam substrates . Compared to IMP-1, the kinetic parameters of IMP-2 were similar overall with some beta-lactam substrates (cefoxitin, ceftazidime, cefepime, and imipenem) but remarkably different with others (ampicillin, carbenicillin, cephaloridine, and meropenem), revealing a functional significance of at least some of the mutations that differentiate the two IMP variants . Present findings suggest that the environmental reservoir of bla(IMP) alleles could be widespread and raise a question about the global risk of their transfer to clinically relevant species.

Antibiot Khimioter, 2000, 45(3), 15 - 9
{The structure and antibiotic sensitivity of the causative agents of community-acquired infectious diseases of bacterial origin in children}; Samsygina GA et al.; Four hundred and forty pediatric patients at the age of 7 days to 15 years with various infections admitted to the Hospital within a month were examined . The biological material was inoculated to blood agar on the first days of the patient admittance to the Hospital and after the growth the organisms were isolated and identified . Antibiotic susceptibility of the isolates was assayed with the disk diffusion method . 479 strains in all were tested . The most frequent cases requiring hospitalization and antibiotic therapy were those of respiratory tract infections (54.09 per cent), urinary tract infections (26.36 per cent), cutaneous and subcutaneous fat diseases, gastrointestinal diseases and others (about 25 per cent of the cases in all) . The main pathogens were Streptococcus viridans, S.aureus and S.epidermidis, as well as Enterobacteriaceae (chiefly E.coli) whose frequencies were practically equal (in 25-35 per cent of the cases) . The Pneumococcus isolates amounted to 6.3 per cent . Nonfermenting bacteria (Pseudomonas aeruginosa and Acinetobacter) and some representatives of Enterobacteriaceae (Citrobacter, Serratia, Morganella) were isolated from 7 per cent of the patients . The frequency of Klebsiella and Enterobacter was about 11 per cent . The main pathogens were tested for their susceptibility to amoxycillin/clavulanic acid, ampicillin, oxacillin and gentamicin . The least active antibiotic was ampicillin . 88.8 per cent of the E.coli isolates and 100 per cent of the Klebsiella, P.mirabilis, Morganella, Citrobacter, Enterobacter and Serratia isolates were resistant to it . 53.2 per cent of the Streptococcus isolates including 64.5 per cent of the Pneumococcus isolates were as well resistant to ampicillin . 59.5 per cent of the Streptococcus isolates (mainly S.viridans and Enterococcus) was susceptible to oxacillin, 22.2 per cent of them being moderately susceptible . 62.5 per cent of the Pneumococcus isolates and 78.1 per cent of the Staphylococcus isolates were also susceptible to oxacillin . The highest susceptibility of the isolates was that to amoxycillin/clavulanic acid, i.e . 90.1 per cent of the strains, 79.9 per cent of them being highly susceptible . All the isolates of Citrobacter, Serratia and Morganella and some isolates of P.aeruginosa, Acinetobacter, Enterobacter, Klebsiella and E.coli were resistant to amoxycillin/clavulanic acid . As for the latter 5 organisms their susceptibility to amoxycillin/clavulanic acid was comparable with that to gentamicin . The susceptibility of the Streptococcus and Staphylococcus isolates to amoxycillin/clavulanic acid was significantly much higher than that to oxacillin, gentamicin and ampicillin: 93 per cent of the Streptococcus isolates (62.7 per cent of the Pneumococcus isolates) and 90.7 per cent of the Staphylococcus isolates.

Arch Microbiol, 2000 Mar, 173(3), 220 - 8
comB, a novel competence gene required for natural transformation of Acinetobacter sp . BD413: identification, characterization, and analysis of growth-phase-dependent regulation; Herzberg C et al.; Here we describe five tandemly arranged and converging ORFs in Acinetobacter sp . BD413, namely lytB, orfY, orfX, comB, and orfZ, located upstream of the previously identified competence gene comC . The N-termini of the deduced proteins OrfY and ComB exhibit the conserved endopeptidase cleavage motifs of prepilin proteins; the deduced protein ComB is similar to type IV pilins . LytB is similar to the Escherichia coli LytB, which has been implicated in the stringent response . No homologues of OrfX, OrfY and OrfZ could be identified . A mutation in orfY or orfZ led to 100-fold reduced transformation frequencies and a mutation in comB resulted in a non-competent phenotype . Disruption of lytB did not affect the natural transformation phenotype . Complementation studies clearly demonstrated that comB is involved in natural transformation, whereas the transformation-deficient phenotypes of orfY and orfZ mutants were due to polar effects on comB and comC, respectively . Analyses of the twitching motility phenotype and of the ultrastructure of the noncompetent comB mutant suggested that the competence gene comB is not essential for the biogenesis of type IV pili and expression of the type IV pili-associated property of twitching motility . Transcriptional fusions between comB and a promoter-free lacZ gene were constructed, and analysis of growth-phase-dependent transcription revealed increased expression of comB during prolonged exponential and stationary phases.

Rev Med Chir Soc Med Nat Iasi, 1999 Jul-Dec, 103(3-4), 158 - 60
{The clinical picture, treatment and prognosis of meningitis due to anaerobic and nonfermentative bacteria}; Luca C et al.; OBJECTIVES: The study of incidence, clinical manifestations and prognosis of meningitis with anaerobic and non-fermentative bacteria . MATERIAL AND METHOD: Retrospective study of 10 patients with severe forms of purulent meningitis admitted in the Hospital of Infectious Diseases of Iasi, during 1.01.1990-31.12.1998 . RESULTS: 3 of them were diagnosed with etiology with polymicrobial flora and the rest had etiology with: Peptostreptococcus (2 cases), Acinetobacter calcoaceticus (4 cases), Eikenella corrodens (1 case) . The majority were male sex (8 cases), and from rural area (9 cases) . The age of patients ranged from 2.5 to 59 years (the majority being adults of group of age 50-60 years) . The gate of entrance was: iatrogenic in the majority of cases (6 cases), posttraumatic (2 cases) and othogen (2 cases); 3 cases being with cerebrospinal fluid fistula and 8 patients being in coma . The factors associated with poor prognosis were: the immunosuppression (chronic etilism--4 cases; bronchopneumonia--2 cases, pulmonary cancer--1 case) and the presence of the focal neurological findings on the noser of illness . The diagnosis was established by clinical characters and confirmed by isolating germs from cerebrospinal fluid . The treatment was done at the beginning with first intervention antibiotic association with a high spectrum and then according to the antibiogramme . The evolution was severe even under treatment with 3 deaths, the mortality being of 30.0% . CONCLUSIONS: We wished to present these cases as a general remark on the severity of illness, generally appeared on a suppressed ground, together with the rarity of those germs implicated in the etiology of purulent meningitis.

FEMS Microbiol Lett, 2000 Apr 15, 185(2), 151 - 6
Effect of Mg(2+) ion in protein secretion by magnesium-resistant strains of Pseudomonas aeruginosa and Vibrio parahaemolyticus isolated from the coastal water of Haldia port; Bhattacharya M et al.; A rapidly growing industrial complex including oil refineries and chemical industries has developed around the coastal area of Haldia port in the district of Midnapore, West Bengal, India . The coastal water is highly polluted with industrial wastes along with petroleum hydrocarbons . The bacteria isolated from the different sites of the coastal waters were Escherichia coli, Alcaligenes, Acinetobacter, Klebsiella spp., Micrococcus spp., Vibrio spp., Pseudomonas aeruginosa and Vibrio parahaemolyticus . The salinity of the water during the time of collection of samples around the port area was 8 . 2 ppt . Among the isolated organisms, only two isolates, P . aeruginosa and V . parahaemolyticus, showed growth at 300 mM Mg(2+) ion concentration . However, a 3 mM Mg(2+) concentration was detected in the coastal water whereas other metal ion concentrations were less than 3x10(-5) mM . Resistance to Mg(2+) (300 mM) was determined by a 5.5-kb plasmid . A large amount of a 40-kDa outer membrane protein, which was highly soluble in 1 M MgCl(2), was isolated from both V . parahaemolyticus and P . aeruginosa . The secretion of proteins in the culture supernatant of V . parahaemolyticus was highly increased when the cells were grown in the presence of 300 mM Mg(2+), whereas very low secretion was observed in the same concentration of Mg(2+) in the case of P . aeruginosa . Mg(2+) may act as a specific release factor in protein secretion by V . parahaemolyticus strains.

East Afr Med J, 1999 May, 76(5), 243 - 6
In vitro susceptibility of gram-negative bacterial isolates to chlorhexidine gluconate; Mengistu Y et al.; OBJECTIVE: To investigate the susceptibility of clinical isolates of gram-negative bacteria to chlorhexidine gluconate . DESIGN: Prospective laboratory study . SETTING: Tikur Anbessa Hospital, Addis Ababa, Ethiopia . SUBJECTS: Clinical specimens from 443 hospital patients . MAIN OUTCOME MEASURES: Significant number of gram negative bacteria were not inhibited by chlorhexidine gluconate (0.02-0.05%) used for antisepsis . RESULTS: Four hundred and forty three strains of gram-negative bacteria were isolated from Tikur Anbessa Hospital patients . Escherichia coli (31.6%) and Klebsiella pneumoniae (23%) were the most frequently isolated bacteria followed by Proteus species (13.3%), Pseudomonas species (9.2%), and Citrobacter species (6.1%) . Each organism was tested to chlorhexidine gluconate (CHG), minimum inhibitory concentration (MIC) ranging from 0.0001% to 1%w/v . All Salmonella species and E . coli were inhibited by CHG, MIC < or = 0.01% . Twenty nine per cent of Acinetobacter, 28% of K . pneumoniae and Enterobacter species and 19-25% of Pseudomonas, Proteus and Providencia species were only inhibited at high concentrations of CHG (> or = 0.1%) . CONCLUSION: Our results showed that a significant number of the gram-negative bacterial isolates were not inhibited by CHG at the concentration used for disinfection of wounds or instruments (MIC 0.02-0.05% w/v) . It is therefore important to select appropriate concentration of this disinfectant and rationally use it for disinfection and hospital hygiene . Continuing follow up and surveillance is also needed to detect resistant bacteria to chlorhexidine or other disinfectants in time.

Med Pregl, 1999 Nov-Dec, 52(11-12), 475 - 83
The frequency, characteristics and outcome of infections in patients with acute nonlymphoblastic leukemias; Savic A et al.; A retrospective study was conducted in 91 patients treated at the Clinic of Hematology in Novi Sad in the period January 1, 1994,-November 15, 1997 . The frequency, types, characteristics and outcome of infections were examined . The causative microorganism was determined in 65% of 133 febrile episodes, in 55% Gram-negative bacteria, 39% Gram-positive bacteria and in 6% fungi . Gram-negative bacteria were causative microorganisms in 80% of pneumonia . 77% of skin infections and 93% of urinary infections . Gram-positive bacteria were causative microorganisms in 53% of sepsis, Gram-negative in 41% of sepsis and Candida in 6% . The significant resistance to antibiotics was present in 47% of Gram-negative sepsis (causative microorganisms were Pseudomonas aeruginosa and Acinetobacter species) and in 18% of Gram-positive sepsis (susceptibility to imipenem only in Gram-negative sepsis and susceptibility to vankomycin in Gram-positive sepsis) . Infections were the cause of death in 62.8% of patients.

Ceska Slov Farm, 1999 Nov, 48(6), 272 - 5
{In vitro effect of quinolones on the hydrophobicity of Acinetobacter baumannii}; Hostacka A; Effects of subinhibitory concentrations (sub-MICs) (1/4, 1/8, 1/16 or 1/32 of the MICs) of four quinolone antibiotics on surface hydrophobicity of two Acinetobacter baumannii strains (R1 and R2) were tested . Hydrophobicity was evaluated by adherence of bacteria to xylene and their aggregation in ammonium sulphate solutions . Norfloxacin in concentrations of 1/4 or 1/8 of the MIC decreased hydrophobicity of R1 strain and of R2 strain in concentration of 1/16 of the MIC . Ciprofloxacin was efficient for both strains mainly in concentration of 1/4 of their MICs . Enoxacin (1/8 MIC) more effectively reduced hydrophobic properties only in R2 strain . The other concentrations of the above-mentioned antibiotics as well as all tested concentrations of pefloxacin practically did not affect bacterial surface hydrophobicity.

J Antimicrob Chemother, 2000 Apr, 45(4), 493 - 501
Imipenem, doxycycline and amikacin in monotherapy and in combination in Acinetobacter baumannii experimental pneumonia; Rodriguez-Hernandez MJ et al.; Acinetobacter baumannii is a common cause of nosocomial pneumonia and other nosocomial infections . Multiresistant A . baumannii has also a high prevalence, which can make effective treatment difficult . We designed a new model of A . baumannii experimental pneumonia using C57BL/6 immunocompetent mice . This model was used to compare the efficacy of imipenem, doxycycline and amikacin in monotherapy, and the combination of imipenem plus amikacin and doxycycline plus amikacin . Doxycycline plus amikacin were synergic in vitro after 24 h incubation, whereas imipenem plus amikacin showed no in vitro synergy . The number of sterile lungs and the lung clearance of A . baumannii were greater in the group treated with imipenem than in those treated with amikacin or doxycycline in monotherapy (P < 0.05) . The combination of imipenem plus amikacin and doxycycline plus amikacin was no more effective than imipenem alone in the clearance of organisms from lungs (2.42 +/- 1.46 cfu/g versus 2.7 +/- 1.5 cfu/g versus 1.23 +/- 1.02 cfu/g) . These results suggest that the addition of amikacin does not improve the results obtained by imipenem monotherapy . Doxycycline plus amikacin is an alternative to imipenem in the therapy of A . baumannii pneumonia.

J Antimicrob Chemother, 2000 Apr, 45(4), 437 - 46
In vitro antibacterial spectrum of a new broad-spectrum 8-methoxy fluoroquinolone, gatifloxacin; Fung-Tomc J et al.; The in vitro antibacterial spectrum of gatifloxacin was compared with those of ciprofloxacin and ofloxacin . Gatifloxacin was two- to four-fold more potent than comparator quinolones against staphylococci, streptococci, pneumococci and enterococci (gatifloxacin MIC90s, < or =1 mg/L, except 4 mg/L against methicillin-resistant Staphylococcus aureus and Enterococcus faecium) . Gatifloxacin was two-fold less potent than ciprofloxacin, and the same as or two-fold more potent than ofloxacin against Enterobacteriaceae (MIC90s, 0.06-0.5 mg/L against most members of the Enterobacteriaceae and < or =1 mg/L against Proteus/Morganella spp.) . Relative to the comparator quinolones, gatifloxacin was two- to four-fold more potent against Providencia spp., and had good potency against Acinetobacter spp . (MIC90s, 0.25-1 mg/L) . Gatifloxacin and ofloxacin had similar anti-pseudomonal potency, with corresponding MIC90s of 4, 8 and 0.25 mg/L for Pseudomonas aeruginosa, Pseudomonas fluorescens and Pseudomonas stutzeri, while ciprofloxacin had two- to eight-fold more potency . The three quinolones were equipotent against Burkholderia cepacia (MIC90s, 8 mg/L), but gatifloxacin was two-fold more potent against Stenotrophomonas maltophilia (MIC90, 4 mg/L) . Gatifloxacin was highly potent (MIC90s, 0.03-0.06 mg/L) against Haemophilus influenzae, Legionella spp., Helicobacter pylori and had at least eight-fold better anti-chlamydial and anti-mycoplasma potency (gatifloxacin MIC90s, 0.13 mg/L) . The higher quinolone MICs for ureaplasma (MIC90s, 4-8 mg/L) may be due to the acidic pH of the ureaplasma test medium, which antagonizes quinolones . Like other quinolones, gatifloxacin had poor potency against Mycobacterium avium-intracellulare, though it was eight- to 16-fold more potent against Mycobacterium tuberculosis (MIC90, 0.25 mg/L) . Of the three quinolones, only gatifloxacin had activity against Bacteroides fragilis and Clostridium difficile . In summary, gatifloxacin is a broad-spectrum 8-methoxy fluoroquinolone that is more potent than ciprofloxacin and ofloxacin against Gram-positive bacteria, chlamydia, mycoplasma, mycobacteria and anaerobes.

Diagn Microbiol Infect Dis, 2000 Jan, 36(1), 19 - 36
Antimicrobial activity and spectrum of the new glycylcycline, GAR-936 tested against 1,203 recent clinical bacterial isolates; Gales AC et al.; The in vitro activity of GAR-936, a new semisynthetic glycylcycline, was evaluated in comparison with two tetracyclines and several other antimicrobial agents . A total of 1,203 recent clinical isolates were tested by reference broth or agar dilution methods . Among the members of the family Enterobacteriaceae, GAR-936 was generally two- to four-fold more active than minocycline, and two- to 16-fold more active than tetracycline . All enteric bacilli MIC90 results were < or = 4 microg/mL; the exception being Proteus mirabilis and indole-positive Proteae (> or = 8 microg/mL) . GAR-936 demonstrated excellent activity against all gram-positive cocci with 90% of the penicillin-resistant Streptococcus pneumoniae isolates inhibited at 0.03 microg/ml, while the same isolates had a MIC90 of 8 and > 8 microg/mL for minocycline and tetracycline, respectively . All Enterococcus spp., including vancomycin-resistant isolates, were inhibited at 0.25 microg/mL of GAR-936 (MIC90, 0.12 or 0.25 microg/mL) . Although GAR-936 (MIC50, 0.25 microg/mL) was two-fold less active than minocycline (MIC50, 0.12 microg/mL) against oxacillin-resistant Staphylococcus aureus, all isolates were inhibited at < or = 0.25 microg/mL . GAR-936 demonstrated good activity against nonfermentative bacteria such as Acinetobacter spp . (MIC90, 2 microg/ml) and Stenotrophomonas maltophilia (MIC90, 4 microg/mL), but the compound exhibited only modest activity against Pseudomonas aeruginosa (MIC50, 8 microg/mL) . Haemophilus influenzae (MIC90, 1-2 microg/mL), Moraxella catarrhalis (MIC90, 0.12 microg/mL), and various Neisseria spp . (MIC90, 0.12-0.5 microg/mL) were susceptible to GAR-936 . These results indicate that GAR-936 has potent in vitro activity against a wide range of clinically important pathogenic bacteria, and that several gram-positive and -negative isolates resistant to older tetracyclines and other drug classes remain susceptible to GAR-936, the newest glycylcycline candidate for clinical use.

Acta Univ Palacki Olomuc Fac Med, 1999, 142, 73 - 7
Characteristics of Acinetobacter strains (phenotype classification, antibiotic susceptibility and production of beta-lactamases) isolated from haemocultures from patients at the Teaching Hospital in Olomouc; Hejnar P et al.; A total of 85 strains of the genus Acinetobacter were isolated from haemocultures at the Institute of Microbiology of the Teaching Hospital in Olomouc over the period January 1993 to June 1997 . Sixty-two (73.0%) strains of the Acinetobacter calcoaceticus-baumannii complex (Acb complex) were the most frequent . In 3 (3.5%) strains it was impossible to decide whether they belonged to the Acb complex . Other acinetobacter species were represented by 20 (23.5%) strains . The greatest amount (28.2%) of these strains was collected from the Clinic of Internal Medicine . Leukemias, lymphomas and myelodysplastic syndromes were the most frequent clinical diagnoses (20.0%) of the patients with a positive haemoculture . The most effective antimicrobial preparations tested were as follows: meropenem (98.8% of susceptible strains), colistin (94.1%), quinolones (90.6-94.1% according to the type of agent) and amikacin (91.8%) . The Acb complex strains were less susceptible to antimicrobial agents than other acinetobacters . Production of inductive chromosomal beta-lactamases AmpC was proved in 42 (49.4%) strains whilst no occurrence of extended-spectrum beta-lactamases (ESBL) in the isolated organisms was recorded.

Acta Chir Plast, 1999, 41(4), 112 - 6
Changing pattern of infection in the Bratislava Burn Center; Koller J et al.; Infection still remains one of the major problems in burn treatment . The authors investigated the occurrence of burn wound pathogens in burn wound biopsies and/or semiquantitative wound surface off-prints . As the results have shown, trends of a decreased contribution of "classical pathogens", like Staphylococcus aureus and Pseudomonas aeruginosa, to burn wound infections were observed . The role of "other pathogens", like Enterobacter, Acinetobacter, etc., which were quite rare in the past, is on the opposite, increasing . One of the explanations can be the increasing rate of early surgical treatment methods of deep burns . The results were in accordance with similar studies from other burn centres.

J Microbiol Methods, 2000 Mar, 40(1), 67 - 77
Flow cytometric techniques to characterise physiological states of Acinetobacter calcoaceticus; Muller S et al.; Monitoring biotechnological processes involves acquiring information about key metabolic events and, ideally, single cell states should be determined to obtain comprehensive data on the physiological status of the surveyed population . In this paper, growth stages of the strain Acinetobacter calcoaceticus 69-V were characterised at the single cell level using flow cytometry . Four methods for analysing bacterial cellular characteristics by fluorescence were compared with respect to their sensitivity to changes in the physiological states induced by changing micro-environmental conditions . DNA analysis was confirmed to be highly informative with regard to the multiplication activity of the population . Measuring the membrane potential related fluorescence intensity (MPRFI) and the rRNA content were found to be useful for describing high-active cell states . A method for the measurement of the fluidity related fluorescence intensity (FRFI) was developed, since it allowed changes in the fluidity of the bacterial membrane to be detected, and thereby provided a valuable means of tracking adaptation of the population to micro-environmental deviations from optimal growth conditions.

Infect Dis Clin North Am, 2000 Mar, 14(1), 67 - 81, viii
Bacterial resistance to antimicrobial agents in Latin America . The giant is awakening; Guzman-Blanco M et al.; Resistant bacteria are emerging in Latin America as a real threat to the favorable outcome of infections in community- and hospital-acquired infections . Despite present extensive surveillance, healthcare workers who most need the information may be unaware of this growing problem . Outbreaks of meningococci with diminished susceptibility to penicillin have been reported in the region; a constant increase of resistance to penicillin in pneumococci and poor activity of commonly used oral antibiotics for the treatment of community-acquired urinary tract infections have made the treatment of these infections more difficult . Reports from tertiary hospitals are similar to many other areas of the world, with increasing frequency of Klebsiella pneumoniae-carrying extended-spectrum beta-lactamase, multiresistant strains of Pseudomonas aeruginosa and Acinetobacter baumanni in ICU settings, and reports of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci . A surveillance network readily accessible to those who prescribe antibiotics in Latin America is highly desirable.

Acta Microbiol Immunol Hung, 2000, 47(1), 15 - 20
Effect of aminoglycosides on surface hydrophobicity of Acinetobacter baumannii; Hostacka A; Effects of amikacin, gentamicin, netilmicin and tobramycin at subinhibitory concentrations (sub-MICs) (11/4, 1/8, 1/16 or 1/32 of their MICs) on the cell surface hydrophobicity of two Acinetobacter baumannii strains (7194 and 16265) were evaluated . Hydrophobicity was determined by two different methods - by adherence of bacteria to hydrocarbon (xylene) and by aggregation of bacteria in ammonium sulphate solutions at various concentrations . The adherence of A . baumannii strains to xylene decreased, mainly, after treatment with netilmicin at 1/4, 1/8 or 1/16 of the MIC (to 6.4%, 17.0% or 24.5% of the control value) (strain 7194) and after treatment with amikacin and gentamicin at 1/4 of their MICs (to 58.4% or 54.4%) (strain 16265) . A decrease in surface hydrophobicity of exposed strains under these conditions was shown in salting-out test, too . Tobramycin reduced hydrophobic properties of A . baumannii strains at all tested sub-MICs to only a small extent.

Int J Antimicrob Agents, 2000 Jan, 13(3), 175 - 82
Outer-membrane proteins pattern and detection of beta-lactamases in clinical isolates of imipenem-resistant Acinetobacter baumannii from Brazil; Costa SF et al.; In order to compare imipenem-sensitive and -resistant Acinetobacter baumannii strains isolated from three patients, ribotyping, plasmid, beta-lactamase detection and outer-membrane analysis were performed . Ribotyping and the use of a beta-lactam during the period when the strains were isolated suggested that they had a common origin and that resistance occurred in vivo . Outer membrane analysis showed no difference between susceptible and resistant strains with the exception of an A2 imipenem-resistant strain that lost a protein band of 31-36 kDa . Beta-lactamases were detected using isoelectric focusing in all strains (pI of 7.4) . In addition, two beta-lactamases (pI of 5.9 and 6.7) were found in imipenem-resistant isolates . The double-disc technique demonstrated the presence of a beta-lactamase capable of imipenem inactivation in resistant strains . Plasmid analysis showed that all susceptible strains had the same pattern, one resistant strain did not have any plasmid, one had the same plasmid pattern of its susceptible pair and only one had a different pattern when compared with its susceptible pair.

Antimicrob Agents Chemother, 2000 Apr, 44(4), 1070 - 4
Nucleotide sequence of the bla(RTG-2) (CARB-5) gene and phylogeny of a new group of carbenicillinases; Choury D et al.; We determined the nucleotide sequence of the bla gene for the Acinetobacter calcoaceticus beta-lactamase previously described as CARB-5 . Alignment of the deduced amino acid sequence with those of known beta-lactamases revealed that CARB-5 possesses an RTG triad in box VII, as described for the Proteus mirabilis GN79 enzyme, instead of the RSG consensus characteristic of the other carbenicillinases . Phylogenetic studies showed that these RTG enzymes constitute a new, separate group, possibly ancestors of the carbenicillinase family.

Antimicrob Agents Chemother, 2000 Apr, 44(4), 1035 - 40
In vitro activities of nontraditional antimicrobials against multiresistant Acinetobacter baumannii strains isolated in an intensive care unit outbreak; Appleman MD et al.; Fifteen multiresistant Acinetobacter baumannii isolates from patients in intensive care units and 14 nonoutbreak strains were tested to determine in vitro activities of nontraditional antimicrobials, including cefepime, meropenem, netilmicin, azithromycin, doxycycline, rifampin, sulbactam, and trovafloxacin . The latter five drugs were further tested against four of the strains for bactericidal or bacteriostatic activity by performing kill-curve studies at 0.5, 1, 2, and 4 times their MICs . In addition, novel combinations of drugs with sulbactam were examined for synergistic interactions by using a checkerboard configuration . MICs at which 90% of the isolates tested were inhibited for antimicrobials showing activity against the multiresistant A . baumannii strains were as follows (in parentheses): doxycycline (1 microg/ml), azithromycin (4 microg/ml), netilmicin (1 microg/ml), rifampin (8 microg/ml), polymyxin (0.8 U/ml), meropenem (4 microg/ml), trovafloxacin (4 microg/ml), and sulbactam (8 microg/ml) . In the kill-curve studies, azithromycin and rifampin were rapidly bactericidal while sulbactam was more slowly bactericidal . Trovafloxacin and doxycycline were bacteriostatic . None of the antimicrobials tested were bactericidal against all strains tested . The synergy studies demonstrated that the combinations of sulbactam with azithromycin, rifampin, doxycycline, or trovafloxacin were generally additive or indifferent.

Clin Infect Dis, 2000 Mar, 30(3), 454 - 60
Antimicrobial susceptibility and frequency of occurrence of clinical blood isolates in Europe from the SENTRY antimicrobial surveillance program, 1997 and 1998; Fluit AC et al.; As part of the European arm of the SENTRY Antimicrobial Surveillance Program, 25 European university hospitals referred 9613 blood isolates for in vitro testing against >20 antimicrobial agents . Escherichia coli, Staphylococcus aureus, coagulase-negative Staphylococcus, Pseudomonas aeruginosa, and Klebsiella pneumoniae were the 5 most frequent isolates and accounted for two-thirds of all referrals, with minor regional variation . Of these, approximately 0.36% of E . coli and 16.7% of K . pneumoniae isolates proved to be potential extended-spectrum beta-lactamase producers, and their incidence clearly varied regionally . Quinolone resistance was detected among gram-negative species; in particular, P . aeruginosa and Acinetobacter species . Considerable regional variation was observed in the incidences of methicillin resistance in S . aureus and penicillin resistance in Streptococcus pneumoniae . The incidence of vancomycin resistance in enterococci was relatively low overall and primarily associated with Enterococcus faecium . However, extrapolation of these data to smaller and nonteaching hospitals should be undertaken with caution, since resistance rates may be lower in these facilities.

J Chemother, 1999 Dec, 11(6), 518 - 23
Emerging antimicrobial resistance in the surgical compromised host; Wilson AP; Improvements in the treatment of compromised patients have resulted in their prolonged survival in a debilitated state . Patients have repeated courses of antibiotics and become colonised with multiresistant pathogens during a stay in the intensive care unit . Surgical wound infections can then be very difficult to treat . Methicillin-resistant Staphylococcus aureus is now common although wide variations in prevalence exist between countries and regions . Klebsiella spp with multiple resistance is a common cause of septicemia and can be associated with cephalosporin use . Acinetobacter spp and vancomycin-resistant enterococci can cause infections resistant to all readily available antibiotics . The prevalence of infection with each of these pathogens is increasing . Control measures should include hand washing, universal precautions for infection control, source isolation, restrictive antibiotic policy and antibiotic rotation . Although new agents currently in trials may be effective in the long term, the future for antibiotic treatment or prophylaxis of surgical infections is in doubt.

FEMS Microbiol Ecol, 2000 Mar 1, 31(3), 195 - 205
Three types of phenol and p-cresol catabolism in phenol- and p-cresol-degrading bacteria isolated from river water continuously polluted with phenolic compounds; Heinaru E et al.; A total of 39 phenol- and p-cresol-degraders isolated from the river water continuously polluted with phenolic compounds of oil shale leachate were studied . Species identification by BIOLOG GN analysis revealed 21 strains of Pseudomonas fluorescens (4, 8 and 9 of biotypes A, C and G, respectively), 12 of Pseudomonas mendocina, four of Pseudomonas putida biotype A1, one of Pseudomonas corrugata and one of Acinetobacter genospecies 15 . Computer-assisted analysis of rep-PCR fingerprints clustered the strains into groups with good concordance with the BIOLOG GN data . Three main catabolic types of degradation of phenol and p-cresol were revealed . Type I, or meta-meta type (15 strains), was characterized by meta cleavage of catechol by catechol 2,3-dioxygenase (C23O) during the growth on phenol and p-cresol . These strains carried C23O genes which gave PCR products with specific xylE-gene primers . Type II, or ortho-ortho type (13 strains), was characterized by the degradation of phenol through ortho fission of catechol by catechol 1,2-dioxygenase (C12O) and p-cresol via ortho cleavage of protocatechuic acid by protocatechuate 3,4-dioxygenase (PC34O) . These strains carried phenol monooxygenase gene which gave PCR products with pheA-gene primers . Type III, or meta-ortho type (11 strains), was characterized by the degradation of phenol by C23O and p-cresol via the protocatechuate ortho pathway by the induction of PC34O and this carried C23O genes which gave PCR products with C23O-gene primers, but not with specific xylE-gene primers . In type III strains phenol also induced the p-cresol protocatechuate pathway, as revealed by the induction of p-cresol methylhydroxylase . These results demonstrate multiplicity of catabolic types of degradation of phenol and p-cresol and the existence of characteristic assemblages of species and specific genotypes among the strains isolated from the polluted river water.

J Food Prot, 2000 Mar, 63(3), 315 - 21
Psychrobacters and related bacteria in freshwater fish; Gonzalez CJ et al.; Three phenotypic identification systems were employed to identify 106 strains of gram-negative, nonmotile, aerobic bacteria obtained during iced storage of wild (Salmo trutta and Esox lucius) and farmed (Oncorhynchus mykiss) freshwater fish . Using diagnostic tables and computer-assisted identification, the isolates were Psychrobacter (64 strains), Acinetobacter (24 strains), Moraxella (6 strains), Chryseobacterium (5 strains), Myroides odoratus (2 strains), Flavobacterium (1 strain), Empedobacter (1 strain), and unidentified (3 strains) . Overall similarities of all strains were determined for 108 characters by numerical analysis (simple matching coefficient of similarity {S} and clustering by unweighted pair group average linkage {UPGMA}) . At the 77% similarity level, 92 strains formed nine major clusters (3 or more strains) and four small clusters (2 strains) . Cluster 1 (25 isolates divided into two main subclusters) could be assigned to Psychrobacter phenylpyruvicus, clusters 2 and 3 (26 isolates) were designated as Psychrobacter immobilis, and clusters 4 (3 isolates) and 7 (4 isolates) were identified as Psychrobacter urativorans and Psychrobacter spp., respectively . Clusters 5 (five isolates), 6 (three isolates), and 9 (five isolates) were labeled as Acinetobacter spp., Acinetobacter johnsonii, and Acinetobacter lwoffii, respectively . Cluster 8 (12 isolates), with a high resemblance to Thornley's phenon 4 (a heterogeneous group of bacteria isolated from poultry and related to Acinetobacter), remained unnamed . The restriction pattern was identical for strains grouped into clusters 2 and 3 (P . immobilis) but was different for the remaining Psychrobacter isolates . A large proportion of isolates belonging to the family Moraxellaceae were closely related . Psychrobacters and A . johnsonii were present in freshly caught fish and river water . In the latter stages of storage, P . phenylpyruvicus and acinetobacters tended to decrease, whereas P . immobilis increased.

J Bacteriol, 2000 Apr, 182(7), 2018 - 25
sal genes determining the catabolism of salicylate esters are part of a supraoperonic cluster of catabolic genes in Acinetobacter sp . strain ADP1; Jones RM et al.; A 5-kbp region upstream of the are-ben-cat genes was cloned from Acinetobacter sp . strain ADP1, extending the supraoperonic cluster of catabolic genes to 30 kbp . Four open reading frames, salA, salR, salE, and salD, were identified from the nucleotide sequence . Reverse transcription-PCR studies suggested that these open reading frames are organized into two convergent transcription units, salAR and salDE . The salE gene, encoding a protein of 239 residues, was ligated into expression vector pET5a . Its product, SalE, was shown to have esterase activity against short-chain alkyl esters of 4-nitrophenol but was also able to hydrolyze ethyl salicylate to ethanol and salicylic acid . A mutant of ADP1 with a Km(r) cassette introduced into salE had lost the ability to utilize only ethyl and methyl salicylates of the esters tested as sole carbon sources, and no esterase activity against ethyl salicylate could be detected in cell extracts . SalE was induced during growth on ethyl salicylate but not during growth on salicylate itself . salD encoded a protein of undetermined function with homologies to the Escherichia coli FadL membrane protein, which is involved in facilitating fatty acid transport, and a number of other proteins detected during aromatic catabolism, which may also function in hydrocarbon transport or uptake processes . A Km(r) cassette insertion in salD deleteriously affected cell growth and viability . The salA and salR gene products closely resemble two Pseudomonas proteins, NahG and NahR, respectively encoding salicylate hydroxylase and the LysR family regulator of both salicylate and naphthalene catabolism . salA was cloned into pUC18 together with salR and salE, and its gene product showed salicylate-inducible hydroxylase activity against a range of substituted salicylates, with the same relative specific activities as found in wild-type ADP1 grown on salicylate . Mutations involving insertion of Km(r) cassettes into salA and salR eliminated expression of salicylate hydroxylase activity and the ability to grow on either salicylate or ethyl salicylate . Studies of mutants with disruptions of genes of the beta-ketoadipate pathway with or without an additional salE mutation confirmed that ethyl salicylate and salicylate were channeled into the beta-ketoadipate pathway at the level of catechol and thence dissimilated by the cat gene products . SalR appeared to regulate expression of salA but not salE.

Zentralbl Bakteriol, 2000 Jan, 289(8), 787 - 95
Examination of polyclonal rabbit immune sera against serovars of Acinetobacter baumannii and genospecies 3 for cross-reactions with reference strains of other named/unnamed genospecies of Acinetobacter; Traub WH; Polyclonal rabbit immune sera against 38 serovars of Acinetobacter baumannii and genospecies 13 capable of growth at 44 degrees C and against 26 serovars of genospecies 3 and genospecies 13 incapable of growth at 44 degrees C were examined for serological cross-reactivity with reference strains comprising 17 genospecies (among them 6 named species) of Acinetobacter . Checkerboard agglutination tests yielded very few cross-reactions . Specifically, genospecies 17 cross-reacted weakly with A . baumannii serovar 27; strains genospecies 13 (Bouvet), TU 14, and 'close to TU 13' were strongly agglutinated by antiserum against A . baumannii serovar 18 . Genospecies 14 (Bouvet) yielded a very weak cross-reaction with genospecies 3 serovar 20, and genospecies TU 13 reacted weakly with anti-genospecies 3 serovar 15 serum . The 'between genospecies 1 and 3' reference strain proved to be A . baumannii serovar 5 as determined with absorption tests.

Diagn Microbiol Infect Dis, 2000 Feb, 36(2), 107 - 12
High prevalence of antibiotic resistance of common pathogenic bacteria in Taiwan . The Antibiotic Resistance Study Group of the Infectious Disease Society of the Republic of China; Chang SC et al.; We analyzed the antimicrobial susceptibilities of all clinical isolates of 14 common pathogenic bacteria recovered from patients in eight medical centers in Taiwan during 1995 and 1996 . Susceptibility to commonly used antimicrobial agents was tested by the disk diffusion method as recommended by the National Committee for Clinical Laboratory Standards . Of the Staphylococcus aureus isolates, 59.3% and 62% were oxacillin-resistant in 1995 and 1996, respectively, whereas 63.2% of the coagulase-negative staphylococci isolates during the study period were oxacillin-resistant . The rate of penicillin-resistance among Streptococcus pneumoniae isolates was 39.7% in 1995 and 53.7% in 1996 . Macrolide-resistance was found in 71.4%, 42.1%, and 46.7% of S . pneumoniae, beta-hemolytic streptococci, and viridans streptococci, respectively, in 1996 . Less than 2% of the enterococcal isolates were vancomycin resistant, but 77% of them were gentamicin resistant . Resistance to gentamicin was also common in Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii . Various degrees of resistance to ampicillin, piperacillin, cephalosporins, aztreonam, and ciprofloxacin were detected in Enterobacteriaceae, P . aeruginosa, and A . baumannii . More than 55% of Haemophilus influenzae isolates were ampicillin resistant . In summary, resistance to many antimicrobial agents in various common pathogenic bacteria is very common in Taiwan . Our results implicate that antibiotic resistance in the developing countries need to be monitored closely.

Am J Ophthalmol, 2000 Mar, 129(3), 388 - 90
Postoperative endophthalmitis caused by sequestered Acinetobacter calcoaceticus; Gopal L et al.; PURPOSE:To describe postoperative endophthalmitis caused by sequestered Acinetobacter calcoaceticus.METHOD:Case report . A 40-year-old woman developed recurrence of inflammation after extracapsular cataract extraction with intraocular lens (IOL) implantation . At last recurrence, the capsular bag was studded with white deposits . Intraocular lens was removed along with capsular bag during pars plana vitrectomy.RESULTS:The capsular bag, when cultured, grew A calcoaceticus . The media remained clear with no evidence of recurrence of infection over a 3-month follow-up . CONCLUSION:Postoperative endophthalmitis similar to that caused by sequestered Propionibacterium acnes can be caused by A calcoaceticus.

J Postgrad Med, 1998 Jan-Mar, 44(1), 7 - 13
Bacterial profile and antimicrobial susceptibility pattern in catheter related nosocomial infections; Tullu MS et al.; This prospective study was carried out over a period of 6 months in the Paediatric Intensive Care Unit (PICU) of a tertiary care teaching hospital . The aim of the study was to determine the organisms causing catheter related nosocomial infections in the PICU and to study their antimicrobial susceptibility pattern . Patients with endotracheal intubation, indwelling urinary catheters and central venous catheters (CVC)/venous cutdown catheters were included in the study . Colonization of the endotracheal tube, urinary catheter related infections (UCRI) and colonization of the CVC/venous cutdown catheters was studied . E . coli was the commonest organism colonizing the endotracheal tube tip with maximum susceptibility to cefotaxime and amikacin . E . coli was also was the commonest organism causing UCRI with maximum susceptibility to nitrofurantoin and amikacin . Acinetobacter was the commonest organism colonizing the CVC/venous cutdown catheters with maximum susceptibility to ciprofloxacin . All these sites of catheter related infections considered together, E . coli and Klebsiella were the commonest nosocomial organisms . Both had maximum susceptibility to amikacin . Methicillin resistant Staphylococcus aureus (MRSA) was isolated only from one culture . All the organisms had a poor susceptibility to cefazolin and amoxycillin . A knowledge of the resident microbial flora and their antimicrobial susceptibility pattern is necessary for formulating a rational antibiotic policy in an ICU.

Clin Diagn Lab Immunol, 2000 Mar, 7(2), 293 - 5
Antibody response to lipopolysaccharide in patients colonized or infected with an endemic strain of Acinetobacter genomic species 13 sensu Tjernberg and Ursing; Pantophlet R et al.; The levels of antilipopolysaccharide (anti-LPS) antibodies in patients colonized with an endemic Acinetobacter strain were compared to those in patients with bloodstream infections . Seropositivity and seronegativity correlated with positive and negative blood cultures, respectively, indicating that determination of the level of anti-LPS antibodies is useful for diagnosing Acinetobacter infections.

Methods Find Exp Clin Pharmacol, 1999 Dec, 21(10), 653 - 7
Effect of amikacin on cytotoxic activity and hydrophobicity of Acinetobacter baumannii; Hostacka A et al.; Effect of amikacin at suprainhibitory (2 or 4 x MIC) or supra-subinhibitory concentrations (2 or 4 x MIC + 0.2 x MIC) on bacterial growth, cytotoxicity and cell surface hydrophobicity of three Acinetobacter baumannii strains was studied . Amikacin at suprainhibitory concentrations induced postantibiotic effects (PAEs; suppression of bacterial growth after short time exposure of bacteria to the antibiotic) against all A . baumannii strains . PAEs ranged from 1.2 to 2.9 h (2 x MIC) and 3.5 to 6.3 h (4 x MIC) . Supra-subinhibitory concentrations of amikacin (2 x MIC + 0.2 x MIC) manifested a more significant delay of bacterial regrowth (PA SMEs) for two strains (6.6 or 7.5 h) in comparison with PAEs . One strain under these conditions as well as all strains treated with amikacin at 4 x MIC + 0.2 x MIC did not show any regrowth . Amikacin at all concentrations tested significantly reduced cytotoxic activity of A . baumannii evaluated on alveolar epithelial type II cells . Survival of type II cells after application of antibiotic-treated A . baumannii was in the range of 88 to 101% of the control cells . Cell surface hydrophobicity of amikacin-treated bacteria was practically unchanged varying between 94 and 100.9% as compared to the controls.

Appl Environ Microbiol, 2000 Mar, 66(3), 1237 - 42
Transformation of Acinetobacter sp . strain BD413(pFG4DeltanptII) with transgenic plant DNA in soil microcosms and effects of kanamycin on selection of transformants; Nielsen KM et al.; Here we show that horizontal transfer of DNA, extracted from transgenic sugar beets, to bacteria, based on homologous recombination, can occur in soil . Restoration of a 317-bp-deleted nptII gene in Acinetobacter sp . strain BD413(pFG4) cells incubated in sterile soil microcosms was detected after addition of nutrients and transgenic plant DNA encoding a functional nptII gene conferring bacterial kanamycin resistance . Selective effects of the addition of kanamycin on the population dynamics of Acinetobacter sp . cells in soil were found, and high concentrations of kanamycin reduced the CFU of Acinetobacter sp . cells from 10(9) CFU/g of soil to below detection . In contrast to a chromosomal nptII-encoded kanamycin resistance, the pFG4-generated resistance was found to be unstable over a 31-day incubation period in vitro.

Infection, 2000 Jan-Feb, 28(1), 8 - 12
Mixed infection in adult bacterial meningitis; Chang WN et al.; 12 adult patients suffering from bacterial meningitis caused by mixed infection were identified at Kaohsiung Chang Gung Memorial Hospital over a period of 13 years (1986-1998), and they accounted for 6.5% (12/184) of our culture-proven adult bacterial meningitis . The 12 cases included seven males and five females, aged 17-74 years . Six of the 12 cases had community-acquired infections and the other six had nosocomially-acquired infections . Ten of the 12 cases had associated underlying diseases, with head trauma and/or neurosurgical procedure being the most frequent . Both gram-negative and gram-positive pathogens were identified in these 12 cases with gram-negative pathogens outnumbering the gram-positive ones . The implicated pathogens, starting with the most frequent, included Enterobacter species (Enterobacter cloacae, Enterobacter aerogenes), Klebsiella species (Klebsiella pneumoniae, Klebsiella oxytoca), Escherichia coli, Staphylococcus species (Staphylococcus aureus, Staphylococcus haemolyticus), Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus, Serratia marcescens, Citrobacter diversus, Proteus mirabilis, Streptococcus viridans and Neisseria meningitidis . Six of the 12 cases were found to have multi-antibiotic-resistant strains, which included E . cloacae in one, A . baumannii in one, K . pneumoniae in one and S . aureus in three . The management of these 12 cases included appropriate antibiotics and neurosurgical procedures including shunt revision . Despite the complexity of implicated pathogens and the high incidence of emergence of resistant strains, the overall mortality rate (8.3%, 1/12) was not higher than that in adult bacterial meningitis . However, complete recuperation was difficult in adult patients with mixed bacterial meningitis.

Can J Microbiol, 1999 Dec, 45(12), 995 - 1000
Removal of silver from photographic wastewater effluent using Acinetobacter baumannii BL54; Shakibaie MR et al.; Acinetobacter baumannii BL54, a silver (Ag) resistant micro-organism was isolated from clinical samples collected at the Armed Forces Medical College hospital in Pune, India . The strain BL54 removed a high quantity of silver (2.85 mg/g biomass) from photographic wastewater effluent . Treatment of the cells with 10 mM EDTA or agitating the culture did not affect the removal process, while altering pH of the wastewater or pre-treating the cells with 0.5 mM 2,4-dinitrophenol (DNP), 20 microM N,N'-dicyclohexylcarbodiimide (DCC), 25 micrograms/mL cefotaxime, and polymyxin-B resulted in considerable decrease in removal of silver by the organism . Dead cells, or a Ags plasmid-cured derivative (BL54.1) removed little silver, which was mainly surface bound . The results, compared with accumulation of Ag by a sensitive culture of Escherichia coli K12 J53.2, suggest that A . baumannii BL54 has good potential for bioremediation of silver from photographic wastewater effluents.

J Clin Microbiol, 2000 Mar, 38(3), 1127 - 30
Evaluation of autoSCAN-W/A and the Vitek GNI+ AutoMicrobic system for identification of non-glucose-fermenting gram-negative bacilli; Sung LL et al.; The autoSCAN-W/A (W/A; Dade Behring Microscan Inc., West Sacramento, Calif.) and Vitek AutoMicrobic System (Vitek AMS; bioMerieux Vitek Systems, Inc., Hazelwood, Mo.) are both fully automated microbiology systems . We evaluated the accuracy of these two systems in identifying nonglucose-fermenting gram-negative bacilli . We used the W/A with conventional-panel Neg Combo type 12 and Vitek GNI+ identification systems . A total of 301 isolates from 25 different species were tested . Of these, 299 isolates were identified in the databases of both systems . The conventional biochemical methods were used for reference . The W/A correctly identified 215 isolates (71 . 4%) to the species level at initial testing with a high probability of >/=85% . The Vitek GNI+ correctly identified 216 isolates (71.8%) to the species level at initial testing with a high probability of >/=90% . After additional testing that was recommended by the manufacturer's protocol, the correct identifications of the W/A and Vitek GNI+ improved to 96.0 and 92.3%, respectively . The major misidentified species were Sphingomonas paucimobilis and Agrobacterium radiobacter in the W/A system and Acinetobacter lwoffii, Chryseobacterium indologenes, and Comamonas acidovorans in the Vitek GNI+ system . The error rates were 4.0 and 7.6%, respectively . The overall accuracy for both systems was above 90% if the supplemental tests were applied . There was no significant difference in accuracy (P > 0.05) between the two systems.

J Clin Microbiol, 2000 Mar, 38(3), 1036 - 41
Failure of an automated blood culture system to detect nonfermentative gram-negative bacteria; Klaerner HG et al.; During a 1-year study we observed that both aerobic and anaerobic blood culture bottles from patients were negative by the BacT/Alert system during a 7-day incubation period . However, upon subcultivation of negative bottles, growth of Pseudomonas aeruginosa was detectable . In an attempt to explain this observation, aerobic BacT/Alert Fan bottles were seeded with a defined inoculum (0.5 McFarland standard; 1 ml) of Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, P . aeruginosa, Stenotrophomonas maltophilia, or Acinetobacter baumannii . Half of the inoculated bottles were loaded into the BacT/Alert system immediately, and the remainder were preincubated for 4, 8, 16, and 24 h at 36 degrees C . With preincubation all bottles seeded with the Enterobacteriaceae signaled positive during the next 1.5 h . Organisms in bottles seeded with the nonfermentative species P . aeruginosa and A . baumannii remained undetected by the BacT/Alert system for 7 days . S . maltophilia was detected if the preincubation time was equal or less than 8 h . Without preincubation all bottles seeded with the Enterobacteriaceae or nonfermentative species signaled positive . Since nonfermentative species seem to enter a state of bacteriostasis within the preincubation period, we reasoned that an unknown factor is consumed . Accordingly, a smaller inoculum should allow the detection of nonfermentative species, even after preincubation, and serial dilutions of P . aeruginosa were detected in preincubated bottles . In this case preincubated bottles signaled positive faster than bottles without preincubation . We conclude that all bottles from clinical settings should be subcultured prior to loading to avoid false negatives . An alternative may be preincubation at room temperature.

IUBMB Life, 1999 Sep, 48(3), 339 - 43
Biochemical properties of the protein tyrosine kinase of the bacterium Acinetobacter johnsonii; Grangeasse C et al.; The biochemical properties of the autophosphorylating protein tyrosine kinase of Acinetobacter johnsonii were analyzed in vitro . The study shows that the optimal pH value for the phosphorylation reaction is approximately 7 . The enzyme activity is stimulated by magnesium and, to a lesser extent, by manganese ions, whereas calcium ions have no effect . The phosphorylation process is rapid reaching a maximum in < 2 min, and the enzyme is modified at multiple sites . Interestingly, the bacterial enzyme is insensitive to a series of molecules known to affect the activity of eukaryotic protein tyrosine kinases: genistein, quercetin, tosyllysine chloromethyl ketone, and vanadate . We concluded that, even though the overall phosphorylation reaction catalyzed by the A . johnsonii enzyme is identical to that occurring in eukaryotes, this bacterial kinase exhibits a number of specific properties and therefore probably belongs to a separate group in the general family of protein tyrosine kinases.

J Spinal Cord Med, 1999 Fall, 22(3), 192 - 8
Effect of oral ciprofloxacin on bacterial flora of perineum, urethra, and lower urinary tract in men with spinal cord injury; Waites KB et al.; A study was performed in 25 men with spinal cord injuries undergoing intermittent catheterization whose urine had > or = 10(5) bacterial colonies/ml to determine efficacy of ciprofloxacin in eradicating susceptible organisms from urine, urethra, and perineum . Cultures were obtained prior to, during, and 5 to 7 days after administration of 500 mg twice daily for 10 days . Organisms in urine were also present in the urethra and/or perineum in 20 cases . Susceptible bacteria disappeared from urine in all subjects; but at follow-up 12 had cultures positive for ciprofloxacin-resistant Gram-positive cocci, including 1 with methicillin-resistant Staphylococcus aureus (MRSA), and 2 with ciprofloxacin-resistant Acinetobacter sp . Treatment significantly reduced Gram-negative bacilli in perinea and urethras, but ciprofloxacin-susceptible organisms were replaced by resistant staphylococci, including MRSA, enterococci, and Acinetobacter sp . We support use of ciprofloxacin for treatment of urinary tract infections in persons with spinal cord injury, but in view of supercolonization with resistant organisms, the drug should be reserved for symptomatic persons not likely to respond to other oral agents.

Hunan Yi Ke Da Xue Xue Bao, 1998, 23(5), 453 - 7
{A prospective study on etiologic bacteria in 200 patients with pneumonia}; Luo B et al.; The etiologic agents in 200 patients with pneumonia were studied by the bacterial culture of sputums obtained from the protected single catheter brush or quantitative expectoration at one morning or three-morning expectoration . Two hundred patients were divided into 3 groups . Group 1 was Nosocomial pneumonia (NP patients) . Group 2-1 and Group 2-2 were community acquired pneumonia (CAP patients) . All cases in Group 1 and Group 2-2 suffered from significant underlying diseases while Group 2-1 did not . Gram-negative bacilli(GNB) were isolated from the specimens in Group 1 (87%) and Group 2-2 (75%), respectively . Pseudomonas (30.8%) and klebsiella (20.5%) were the predominant bacteria (in Group 1 and pseudomonas bacteria) in Group 1 and pseudomonas (27.3%), acinetobacter (23%) and kledsiella (18%) were the major etiologic agents in Group 2-2 . The commonest pathogens in Group 2-1 were gram-positive cocci (75%), in which streptococcus (38%) and staphylococcus aureus (25%) were the dominant agents . Compared with Group 2, Group 1 suffered from more mixed bacteria and the agents presented severer drug-resistant . The prognosis was worse in Group 2-2 than in Group 2-1 . The results showed that the GNB pneumonia was more common in the cases who had underlying disease, no matter whether the pneumonia was NP or CAP . These patients had more trouble on their antibiotic therapy . Thus it is important that doctors should use vigorous antibiotics timely while treating these patients' underying diseases.

Indian J Med Res, 1999 Nov, 110, 160 - 3
Biotyping of Acinetobacter species isolated from clinical samples; Gulati S et al.; We used the biotyping scheme using carbohydrate substrate utilization test with 14 carbon sources to speciate Acinetobacter isolates from blood and cerebrospinal fluid cultures of patients admitted to the postoperative neurosurgery ICU during January to November 1996 . Sixty one patients culture positive for Acinetobacter sp . from blood or cerebrospinal fluid were followed up prospectively . Among these patients, 40 patients had clinically diagnosed infections like bacteriemia or meningitis while in 21 patients the isolation was regarded as contaminants . A . baumanniii was the most common isolate associated with clinical infections while A . lwoffii was more likely to be an environmental contaminant.

FEMS Microbiol Lett, 1999 Sep 15, 178(2), 259 - 64
An investigation into the electro-physical characteristics of microbial cells during the metabolism of toxic compounds under conditions of limited O2 availability; Ignatov OV et al.; The purpose of the work reported here was to experimentally clarify the interconnection between changes in the electro-physical characteristics of microbial suspensions and processes of the metabolism of certain toxic compounds (acrylamide and p-nitrophenol (PNP)) in cells containing enzyme systems of the initial metabolism of these compounds . In this work, we used cells of two strains, Acinetobacter calcoaceticum A-122 and Brevibacterium sp . 13PA, which are capable of utilising PNP and acrylamide, respectively, as the sole source of carbon . Suspensions of these cells exhibited appreciable decreases in the magnitude of the electro-optical signal when the microbial metabolism of PNP and acrylamide was inhibited under conditions of limited O2 supply . This attests to a relationship between the electro-physical characteristics of microbial suspensions and cellular metabolic reactions and also to the negligibly small effect that the non-specific interaction of substrate with the cells has on the suspensions' electro-optical properties.

J Bacteriol, 2000 Mar, 182(5), 1383 - 9
Substrate range and genetic analysis of Acinetobacter vanillate demethylase; Morawski B et al.; An Acinetobacter sp . genetic screen was used to probe structure-function relationships in vanillate demethylase, a two-component monooxygenase . Mutants with null, leaky, and heat-sensitive phenotypes were isolated . Missense mutations tended to be clustered in specific regions, most of which make known contributions to catalytic activity . The vanillate analogs m-anisate, m-toluate, and 4-hydroxy-3,5-dimethylbenzoate are substrates of the enzyme and weakly inhibit the metabolism of vanillate by wild-type Acinetobacter bacteria . PCR mutagenesis of vanAB, followed by selection for strains unable to metabolize vanillate, yielded mutant organisms in which vanillate metabolism is more strongly inhibited by the vanillate analogs . Thus, the procedure opens for investigation amino acid residues that may contribute to the binding of either vanillate or its chemical analogs to wild-type and mutant vanillate demethylases . Selection of phenotypic revertants following PCR mutagenesis gave an indication of the extent to which amino acid substitutions can be tolerated at specified positions . In some cases, only true reversion to the original amino acid was observed . In other examples, a range of amino acid substitutions was tolerated . In one instance, phenotypic reversion failed to produce a protein with the original wild-type sequence . In this example, constraints favoring certain nucleotide substitutions appear to be imposed at the DNA level.

Diagn Microbiol Infect Dis, 1999 Dec, 35(4), 325 - 31
In vitro evaluation of cefepime and other broad-spectrum beta-lactams in eight medical centers in Thailand . The Thailand Antimicrobial Resistance Study Group; Biedenbach DJ et al.; The introduction of cephalosporins has had an important impact on the resistance rates to several clinically utilized beta-lactam antimicrobial agents . Most Thailand medical centers have not documented the levels of emerging resistant pathogens causing invasive infections . This study shows using reference-quality MIC techniques (Etest, AB BIODISK, Solna, Sweden), that carbapenem), "fourth-generation" cephalosporins (cefepime and cefpirome), and piperacillin/tazobactam were the most active agents tested against Gram-negative bacilli (Escherichia coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., Serratia spp., indole-positive Proteae, Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin-susceptible Staphylococcus spp . when compared to "third-generation" cephalosporins (ceftazidime and ceftriaxone) . The rank order of activity for all species was imipenem (2.9% resistant) > cefepime (7.7%) > piperacillin/tazobactam (11.1%) > cefpirome (13.4%) > ceftriaxone (21.1%) > ceftazidime (29.9%) . The incidence of extended spectrum beta-lactamase production among E . coli (15.7%) and K . pneumoniae (45.6%) was significant . Cefepime and imipenem were active against the majority of these isolates . The activity of cefepime was also shown to be very good against, 1) organisms capable of producing AmpC enzymes, 2) staphylococci species that were susceptible to oxacillin, and 3) many strains of nonfermentative Gram-negative bacilli . The prevalence of antimicrobial resistance in Thailand seems to be quite high among certain commonly encountered pathogens, and imipenem and cefepime have activity (susceptible and intermediate potency) against > 90% of these organisms.

Diagn Microbiol Infect Dis, 1999 Dec, 35(4), 317 - 23
In vitro evaluation of broad-spectrum beta-lactams tested in medical centers in Korea: role of fourth-generation cephalosporins . The Korean Antimicrobial Resistance Study Group; Lewis MT et al.; Levels of resistance to the "third-generation" cephalosporins among isolates of clinical bacteria in Korea have been increasing at a rapid rate . This study evaluated the activity of cefepime, a "fourth-generation" cephalosporin, and six other broad-spectrum beta-lactam antimicrobials (cefpirome, ceftazidime, ceftriaxone, imipenem, piperacillin/tazobactam 4 micrograms/mL fixed concentration{, oxacillin) against 404 isolates of clinical bacteria from Korea . Susceptibility profiles of each isolate were established using the Etest (AB BIODISK, Solna, Sweden) method of susceptibility testing . Only the carbapenem imipenem was > 90% effective in inhibiting each of the species tested (Escherichia coli, Klebsiella, spp., Citrobacter spp., Enterobacter spp., indole-positive Proteae, Serratia spp., Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin-susceptible staphylococci) . Imipenem was followed by cefepime > cefpirome > piperacillin/tazobactam > ceftazidime > ceftriaxone in overall rank order of usable spectrum against the isolates tested . Extended spectrum beta-lactamase producing phenotypes were much more prevalent among the Klebsiella spp . (48.8%) than the E . coli (5.0%) isolates . Cefepime was much more active than cefpirome, 95.1% susceptible as compared with 70.7% susceptible, against the 41 isolates of Klebsiella spp . The results of this study corroborates findings from earlier studies with levels of resistance to the broad-spectrum beta-lactams in Korea continuing to rise indicating the need for intervention strategies.

Diagn Microbiol Infect Dis, 1999 Dec, 35(4), 307 - 15
In vitro evaluation of cefepime and other broad-spectrum beta-lactams in 22 medical centers in Japan: a phase II trial comparing two annual organism samples . The Japan Antimicrobial Resistance Study Group; Lewis MT et al.; An antimicrobial resistance surveillance study in Japan is presented representing the second year (Phase II) results from 22 medical centers . Each participant laboratory tested (Etest, AB BIODISK, Solna, Sweden) 100 organisms, 10 strains each from 10 species groups including Escherichia coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., indole-positive Proteae, Serratia spp., Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin-susceptible Staphylococcus aureus and coagulase-negative staphylococci . Generally only modest variations in the activity of the studied broad-spectrum beta-lactams was observed compared to the study a year before . Specifically, extended spectrum beta-lactamase (ESBL) rates in E . coli increased (2.9 to 8.1%), but the ESBL rate in Klebsiella spp . fell (8.6 to 5.0%) . Overall the resistance to the beta-lactams varied from a 4.7% decrease (ceftazidime as a consequence of a modified staphylococcal breakpoint criteria) to a 1.0% increase (cefepime, not significant) . The rank order of spectrums in 1998 only changed for cefoperazone-sulbactam (6.1% resistance) that was active against more strains than cefpirome (6.8% resistance) . The overall spectrum rank order for the 1998 Japan sample (% resistance) was: cefepime (3.2%) > imipenem (4.1%) > cefoperazone-sulbactam (6.1%) > cefpirome (6.8%) > ceftazidime (8.4%) > piperacillin (19.9%) . As with a similar study in 1997, imipenem-resistant isolates of P . aeruginosa and Serratia spp . were discovered with metalloenzymes, usually found in the same medical centers . These results demonstrate the continued in vitro activity and potential sustained clinical efficacy of several broad-spectrum beta-lactams in Japan . Rapid emergence of new or novel resistance were not wide spread using a precise quantitative MIC system . Continued surveillance in this nation would be prudent to document the activity of this clinically valuable class of safe, antimicrobial agents.

Diagn Microbiol Infect Dis, 1999 Dec, 35(4), 299 - 305
In vitro evaluation of cefepime and other broad-spectrum beta-lactams in Taiwan medical centers . The Taiwan Antimicrobial Resistance Study Group; Biedenbach DJ et al.; The rates of resistance to commonly used antimicrobial agents have been documented to be at alarmingly high levels in Taiwan for both Gram-positive and Gram-negative species . This study was conducted to assess the current resistance patterns in six medical centers strictly controlled using a common MIC methodology and quality assurance measures . Cefepime, a new clinically introduced broad-spectrum "fourth-generation" cephalosporin, was compared to other members in this class including ceftazidime, cefpirome, ceftriaxone, piperacillin/tazobactam, and imipenem . These antimicrobials were tested against ten species groups of common clinical isolates of Enterobacteriaceae, non-enteric Gram-negative bacilli, and oxacillin-susceptible Staphylococcus spp . The results confirmed that extended spectrum beta-lactamase (ESBL) production in Klebsiella spp . (21.7%) and Escherichia coli (16.7%) was common in all medical centers surveyed . Cefepime was more active against these two species as well as against Amp C producing species, indole-positive Proteae, and Acinetobacter species . The activity of cefepime was comparable although slightly less than that of ceftazidime against Serratia spp . and Pseudomonas aeruginosa strains . All or nearly all staphylococci isolates were susceptible to the beta-lactam antimicrobial agents, except for ceftazidime . Overall, these antimicrobial agents had descending spectrums of activity as follows: imipenem > cefepime > cefpirome > piperacillin/tazobactam > ceftazidime > ceftriaxone for the 550 isolates tested . Cefepime seems to be an important broad-spectrum beta-lactam that can be used with confidence against many important pathogens in Taiwan, including those harboring resistance mechanisms . A continued surveillance program seems prudent for this geographic area.

Diagn Microbiol Infect Dis, 1999 Dec, 35(4), 291 - 7
In vitro evaluation of broad-spectrum beta-lactams in the philippines medical centers: role of fourth-generation cephalosporins . The Philippines Antimicrobial Resistance Study Group; Johnson DM et al.; Cefepime is a potent broad-spectrum "fourth-generation" cephalosporin . The in vitro activity of cefepime was compared to that of cefpirome, ceftazidime, ceftriaxone, imipenem, and piperacillin/tazobactam in a multilaboratory (nine medical centers) Philippine surveillance project from March through October 1998 . A total of 626 Gram-positive and Gram-negative organisms (10 species groups) were tested by the Etest method (AB BIODISK, Solna, Sweden) with results validated by current quality control strain analysis . The overall rank order of usable spectrum of activity was imipenem (4.2% resistance), cefepime (4.5%), cefpirome (5.0%), piperacillin/tazobactam (5.8%) > ceftriaxone (11.2%) > ceftazidime (15.3%), and results did not differ significantly between medical centers . Ceftazidime-resistant Escherichia coli and Klebsiella spp . occurred at rates of 13.3% and 31.1%, respectively, indicating extended-spectrum beta-lactamase (ESBL) activity . Imipenem (100% susceptible), cefepime, and cefpirome (both > or = 97.8% susceptible) were active in vitro against these ESBL phenotypes . Organisms with ceftazidime and/or ceftriaxone-resistant profiles consistent for hyper-production of Amp C cephalosporinases were detected at high rates among the Citrobacter spp . (29.2%) and Enterobacter spp . (45.8%); however, imipenem (100.0% susceptible) and cefepime (98.9%) remained active . Cefepime and imipenem (both 87.5% susceptible) were the most active agents tested against Acinetobacter spp . whereas piperacillin/tazobactam was most effective against P . aeruginosa (80.0% susceptible) . Most tested beta-lactams (except ceftazidime) were active versus oxacillin-susceptible staphylococci . These data should be used as a guide for treatment selection with beta-lactam compounds in the Philippines and to serve as a resistance benchmark in comparisons with future studies in this nation.

Diagn Microbiol Infect Dis, 1999 Dec, 35(4), 285 - 90
In vitro evaluation of cefepime and other broad-spectrum beta-lactams against bacteria from Indonesian medical centers . The Indonesia Antimicrobial Resistance Study Group; Lewis MT et al.; The in vitro activity of cefepime and six other broad-spectrum beta-lactams (cefpirome, ceftazidime, ceftriaxone, imipenem, piperacillin/tazobactam (4 micrograms/mL fixed concentration), and oxacillin was evaluated against 191 isolates of clinical bacteria from Indonesia . Susceptibility testing was performed using Etest (AB BIODISK, Solna, Sweden) methodology . Isolates from 10 species groups were selected for analysis: Escherichia coli, Klebsiella spp., Enterobacter spp., indole-positive Proteae, Serratia spp., Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin-susceptible staphylococci . The overall rank order of spectrum of activity was (% resistant): imipenem (2.2%) > cefepime (7.3%) > piperacillin/tazobactam > cefpirome > ceftazidime > ceftriaxone (16.2%) . The "fourth-generation" cephalosporins, cefepime and cefpirome, displayed greater activity compared with the "third-generation" cephalosporins, ceftazidime, and ceftriaxone, against the 60 E . coli and Klebsiella spp . (30 each) isolates . Phenotypic extended spectrum beta-lactamase occurrence rates among the E . coli and Klebsiella spp . were 23.3 and 33.3%, respectively . Imipenem, cefepime, and cefpirome inhibited 95.7% of the 46 isolates of inducible Amp C cephalosporinase producing Enterobacteriaceae . The majority of the resistance observed to imipenem and cefepime among tested Indoneisian strains was attributable to the nonfermentative Gram-negative bacilli, P . aeruginosa and Acinetobacter spp . These results indicate the presence of beta-lactam resistance in Indonesia and the need for continued antimicrobial surveillance in this nation and region of the world, preferably using accurate quantitative methods.

Diagn Microbiol Infect Dis, 1999 Dec, 35(4), 277 - 83
In vitro evaluation of cefepime and other broad-spectrum beta-lactams for isolates in Malaysia and Singapore medical centers . The Malaysia/Singapore Antimicrobial Resistance Study Group; Biedenbach DJ et al.; The degree of activity of several beta-lactam antimicrobial agents was assessed in Malaysia (four medical centers) and Singapore (two medical centers) tested against 570 clinical isolates . The organisms were tested locally by the Etest (AB BIODISK, Solna, Sweden) method, validated by concurrent use of quality assurance strains (94.1% accurate performance overall) . Ten groups of bacteria were tested against cefepime, cefpirome, ceftazidime, ceftriaxone, piperacillin/tazobactam, oxacillin, and imipenem . Among the tested Escherichia coli and Klebsiella spp., the occurrence of extended spectrum beta-lactamase-producing phenotypes was 5.6-7.0% and 36.7-38.0%, respectively . These strains remained most susceptible (97.5-100.0%) to cefepime and imipenem . Ceftazidime-resistant Enterobacter spp . (21.4% resistant), Citrobacter spp . (15.0%), indole-positive Proteus spp . (6.0%), and Serratia spp . (9.7%) were not resistant to cefepime, and only one strain was resistant to imipenem . Imipenem was generally most potent against non-fermentative Gram-negative bacilli such as Acinetobacter spp . and Pseudomonas aeruginosa . All tested beta-lactams were active against the oxacillin-susceptible staphylococci, except ceftazidime (MIC90, 12 micrograms/mL; 63.2-84.8% susceptibility rates) . Overall spectrums of activity (rank by % resistance) favored imipenem (3.5%) > cefepime (7.7%) > cefpirome (8.9%) > piperacillin/tazobactam (13.2%) > ceftriaxone (14.7%) > ceftazidime (16.9%) . No significant differences in resistance patterns were noted between monitored nations, and these results indicate emerging, elevated rates of resistance versus the studied broad-spectrum beta-lactams in Malaysia and Singapore . Results provide benchmark data for future studies using quantitative methods to determine antimicrobial resistance in these geographic areas.

Folia Microbiol (Praha), 1999, 44(3), 267 - 70
Alterations in surface hydrophobicity of Acinetobacter baumannii induced by meropenem; Hostacka A; Six strains of Acinetobacter baumannii out of eleven strains tested revealed a strong hydrophobic character . This was demonstrated by adherence of bacteria to xylene in the range of 90-94% . Changes in surface hydrophobicity of these strains were studied after treatment with meropenem at subinhibitory concentrations (sub-MICs) (1/4, 1/8, 1/16 or 1/32 of the MICs) . All strains showed a reduced adherence to xylene after the action of meropenem at 1/4 or 1/16 of the MICs . Hydrophobicity of the treated bacteria was decreased to 1.3-70% (1/16 of the MICs) or to 12-86% (1/4 of the MICs), depending on the strain . A decrease in surface hydrophobicity of three strains was also observed after their exposure to meropenem at 1/8 of the MICs (to 18-71% of the control values) . Meropenem at 1/32 of the MICs practically did not affect bacterial hydrophobic properties, with the exception of one strain.

APMIS, 1999 Dec, 107(12), 1079 - 84
The discriminatory power of ribo-PCR compared to conventional ribotyping for epidemiological purposes; Severino P et al.; Molecular typing techniques have become increasingly important for confirmation of epidemiological relationships and delimitation of nosocomial outbreaks . The discriminatory power of the two DNA-based typing methods, conventional ribotyping and ribo-PCR, was assessed to distinguish between selected strains of Acinetobacter calcoaceticus, Enterobacter cloacae, Serratia marcescens and Pseudomonas aeruginosa . Overall, conventional ribotyping was more discriminatory than ribo-PCR.

J Hosp Infect, 1999 Dec, 43(4), 299 - 304
An outbreak of neonatal infection with Acinetobacter linked to contaminated suction catheters; Pillay T et al.; An outbreak of multi-drug resistant Acinetobacter spp . infection in the neonatal unit at King Edward VIII hospital in Durban, South Africa, is described . Nine out of a total of 218 neonates were infected during the study period . The outbreak was characterized by early onset infection {median postnatal age 3 days (range 1-23 days)} in pre-term babies {median gestational age 33 weeks (range 30-35 weeks)} with an attributable mortality of 22% . The source of the outbreak, determined by ribotyping, was presumed to be contaminated suction bottles and catheters in the neonatal admission room . Five neonates were successfully treated with ciprofloxacin and amikacin . Enforcement of strict infection control practices curtailed the outbreak.

J Clin Microbiol, 2000 Feb, 38(2), 526 - 9
Detection of carbapenemase-producing Acinetobacter baumannii in a hospital; Takahashi A et al.; Acinetobacter baumannii strains resistant to both imipenem (IPM) and ceftazidime (CAZ) were isolated from 1994 through 1996 at Gunma University Hospital . Nine isolates from different inpatients were examined for carbapenem-hydrolyzing activity and for the carbapemase gene bla(IMP) by the PCR method . All nine isolates were carbapenemase-producing strains that hydrolyzed IPM and that harbored bla(IMP) . The bla(IMP) gene was transmissible by conjugation to an IPM-susceptible recipient strain of A . baumannii and conferred resistance to IPM, CAZ, cefotaxime (CTX), ampicillin (AMP), and piperacillin (PIP) . Either intermediate or high-level resistance to amikacin (AMK) was transferred from two and five strains, respectively, concomitantly with bla(IMP), and gentamicin (GEN) resistance was also transferred in one instance of high-level AMK resistance . Comparative examination of clinical isolates for resistance patterns to nine drugs, IPM, CAZ, CTX, aztreonam, AMP, PIP, AMK, GEN, and norfloxacin, in addition to pulsed-field gel electrophoresis patterns with NotI-digested genomic DNA, confirmed nosocomial transmission of infections involving carbapenemase-producing A . baumannii strains.

Antimicrob Agents Chemother, 2000 Feb, 44(2), 428 - 32
Cloning, nucleotide sequencing, and analysis of the gene encoding an AmpC beta-lactamase in Acinetobacter baumannii; Bou G et al.; A clinical strain of Acinetobacter baumannii (strain Ab RYC 52763/97) that was isolated during an outbreak in our hospital and that was resistant to all beta-lactam antibiotics tested produced three beta-lactamases: a TEM-1-type (pI, 5.4) plasmid-mediated beta-lactamase, a chromosomally mediated OXA-derived (pI, 9.0) beta-lactamase, and a presumptive chromosomal cephalosporinase (pI, 9.4) . The nucleotide sequence of the chromosomal cephalosporinase gene shows for the first time the gene encoding an AmpC beta-lactamase in A . baumannii . In addition, we report here the biochemical properties of this A . baumannii AmpC beta-lactamase.

Biosci Biotechnol Biochem, 1999 Nov, 63(11), 1959 - 64
Purification and characterization of a novel extracellular lipase catalyzing hydrolysis of oleyl benzoate from Acinetobacter nov . sp . strain KM109; Mitsuhashi K et al.; A new lipase (OBase) which efficiently hydrolyzes oleyl benzoate (OB) was found in the culture supernatant of Acinetobacter nov . sp . strain KM109, a new isolate growing in a minimum medium containing OB as the sole carbon source . OBase was purified to homogeneity with 213-fold purification and 0.8% yield . The molecular weight was estimated to be 62,000 +/- 1,000 by SDS-PAGE under denatured-reduced conditions and to be 50,000 +/- 1,000 by gel-filtration HPLC under native conditions; these findings indicate that OBase is a monomeric enzyme . The optimum temperature and pH of OBase were about 45 degrees C and pH 8 . Temperature and pH stabilities were at or lower than 35 degrees C and in a range of pH 6-8, respectively . Purified OBase preferentially hydrolyzed p-nitrophenyl benzoate (pNPB) over p-nitrophenyl acetate (pNPA) or p-nitrophenyl caproate (pNPC) {pNPB/pNPA = 20 and pNPB/pNPC = 5.4}, indicating that OBase has a high affinity for benzoyl esters . Partial amino-acid sequences of OBase fragments obtained after lysyl endopeptidase treatment showed no similarity with known proteins.

Sci Total Environ, 1999 Dec 15, 243-244, 1 - 8
Interactive effects of selenium and mercury on the restoration potential of leaves of the medicinal plant, Portulaca oleracea Linn; Thangavel P et al.; Leaves of Portulaca oleracea have the potential of regeneration, when grown in a distilled water medium . The two heavy metals, Se and Hg individually and in combination affected both shoot and root development . They completely arrested shoot development at all concentrations . However, they produced concentration-dependent changes in the development of roots, which ranged from their complete inhibition to variation in their initiation time, number and length . Leaf decay was initiated on day 46 in control leaves . Concentration-dependent changes were also observed in the time of initiation and magnitude of decay of leaves . The data indicates that Hg was more toxic than Se . The protective effect of Se against Hg toxicity was evident only at very low concentrations . With further increases in the concentration of both Se and Hg, the protective effect decreased and simultaneously the toxicity increased . Following the decay of leaves, a pink colour development was observed only on leaves exposed to Se . Microbial analysis of leaves showed the presence of Acinetobacter only in Se-exposed leaves . Acinetobacter was therefore considered as probably involved in the formation of elemental Se, which produced a pink colour.

J Hosp Infect, 2000 Jan, 44(1), 27 - 30
Aerators as a reservoir of Acinetobacter junii: an outbreak of bacteraemia in paediatric oncology patients; Kappstein I et al.; Tap water can play a role as a source of nosocomial pathogens, and faucet aerators have occasionally been mentioned in the literature associated with colonization or infection in hospitalized patients . In this study, we report on outbreak of bacteraemia in paediatric oncology patients caused by Acinetobacter junii . Environmental sampling showed the water system to be contaminated with A . junii . Molecular typing using automatic laser fluorescence analysis of randomly amplified polymorphic DNA (RAPD-ALFA) revealed two distinct strains . The outbreak strain, isolated from blood cultures of the affected children, was only found in the water taps of staff rooms . Aerators were commonly found to be contaminated, and more so than water obtained after removal of these devices . We believe that conventional aerators consisting of several wire meshes can serve as a reservoir for low levels of bacteria present in the water system . We recommend, especially for high-risk areas, either that aerators should not be used, or the use of aerators consisting of radially and vertically arranged lamellae, which do not lead to the collection of sediment or water stagnation, and to clean them regularly .

J Chemother, 1999 Oct, 11(5), 357 - 62
Sub-MIC ciprofloxacin effect on fimbrial production by uropathogenic Escherichia coli strains; Lo Bue AM et al.; The urine from 210 patients with acute urinary tract infection (UTI) was examined to study the in vitro effect of ciprofloxacin on fimbriae production by uropathogenic Escherichia coli isolates . Forty-nine bacterial samples of density 10(5) CFU/ml were not considered . From the resulting 161 samples, E . coli was the major strain found, present in 54 samples . Other microoganisms found were: Enterococcus sp . (34 samples), Staphylococcus epidermis (22), yeasts (11), Proteus sp . (11), Pseudomonas sp . (11), Klebsiella sp . (8), Enterobacter sp . (6), Citrobacter sp . (3), and Acinetobacter sp . (1) . The uropathogenic E . coli strains found were P-fimbriated, as demonstrated by hemoagglutination activity against human erythrocytes with and without mannose, SDS-PAGE of fimbrial proteins and transmission electron microscopy (TEM) . All E . coli strains found were exposed in vitro to sub-inhibitory concentrations of ciprofloxacin (1/8 MIC) . Our results showed that: 1) P-fimbriated E . coli is the most prevalent microorganism in acute UTI (34%); 2) exposure to sub-MICs of ciprofloxacin inhibits fimbrial production in 79% of E . coli strains; 3) the pattern of SDS-PAGE fimbrial proteins is modified after exposure; in particular, the most affected synthesis involves the protein at 18 kD known as P-fimbriae.

J Chemother, 1999 Oct, 11(5), 338 - 44
The persistence and clonal spread of a single strain of Acinetobacter 13TU in a large Scottish teaching hospital; McDonald A et al.; This study describes the persistence and spread of a single strain of Acinetobacter 13TU in a large Scottish teaching hospital . Acinetobacter spp . are reported with increasing frequency as a cause of nosocomial infection . The species most implicated in these infections is Acinetobacter baumannii . Following an outbreak of infection with Acinetobacter 13TU within the intensive therapy unit (ITU) of Edinburgh Royal Infirmary (ERI) during 1994-1995, the current epidemiological Acinetobacter situation within the hospital was monitored to determine whether or not control of infection procedures instigated at that time had been successful in controlling the outbreak . Sixty-eight strains of Acinetobacter spp were isolated from clinical specimens received from various wards in the ERI and other associated hospitals over a 7-month period . Each isolate was typed phenotypically by the API20NE system and genotypically by pulsed field gel electrophoresis (PFGE) in order to compare them with the previous outbreak strain . Fifty-three percent of the isolates collected were originally identified as A . junii by API 20 NE, of which 83% (mainly from ITU) were shown to be genotypically related to the previous outbreak strain . Subsequent tDNA fingerprinting of one of the original outbreak strains showed it to be a member of the genospecies 13TU and not A . junii as originally thought.

J Basic Microbiol, 1999, 39(5-6), 325 - 36
Isolation and partial characterization of Bac201: a plasmid-associated bacteriocin-like inhibitory substance from Staphylococcus aureus AB201; Iqbal A et al.; Staphylococcus aureus AB201, a clinical isolate from wound pus, produced a bacteriocin-like inhibitory substance termed as Bac201 that exhibited a broad-spectrum activity against both gram-positive as well as gram-negative bacteria . Among gram-negative bacteria it was active against Neisseria meningitidis and Acinetobacter calcoaceticus both being gram-negative cocci . Inhibition due to the effect of organic acids, hydrogen peroxide, or bacteriophages was excluded . This inhibitory substance could not be induced or eluted . It was partially purified to 80% saturation by ammonium sulfate precipitation resulting in maximum specific activity of 829 AU/mg (25-fold increase) . Proteolytic enzymes rapidly inactivated the antagonistic activity of the partially purified material, whereas glycolytic and lipolytic enzymes had no effect . It remained stable in the presence of mild organic solvents . It could be stored at -20 degrees C without loss of activity, stable at 60 degrees C and 80 degrees C for 30 min, 100 degrees C for 20 min and autoclaving temperature (121 degrees C for 15 min), and exhibited activity within a wide range of pH (2.5-10) . Bac201 had an estimated M(r) of 41kDa, as indicated by activity detection after SDS-PAGE . Temperature-mediated (44 degrees C) plasmid curing studies suggested linkage of bacteriocin production to a 4.8 MDa plasmid . The Bac201 was bactericidal rather than bacteriolytic.

Diagn Microbiol Infect Dis, 1999 Nov, 35(3), 235 - 41
Multicenter evaluation of antimicrobial resistance to six broad-spectrum beta-lactams in Colombia: comparison of data from 1997 and 1998 using the Etest method . The Colombian Antimicrobial Resistance Study Group; Pfaller MA et al.; The minimum inhibitory concentrations of six broad-spectrum beta-lactam antimicrobial agents were determined in 1998 by use of the Etest versus a total of 823 bacteria in 11 Colombian hospital laboratories . These data were compared with results of a similar study conducted in 1997 . The organisms tested included 532 recent clinical isolates of Enterobacteriaceae, 108 Pseudomonas aeruginosa, 94 Acinetobacter species, and 89 oxacillin-susceptible Staphylococcus aureus . Extended-spectrum beta-lactamase production was noted among 27.8 to 33.9% of Escherichia coli isolates and 41.7 to 46.7% of Klebsiella spp . isolates . Hyperproduction of Amp C cephalosporinases was observed with 10.5 to 31.4% of isolates of Enterobacter spp., Serratia spp., and Citrobacter spp . An increase in resistance to all of the beta-lactams was observed among Enterobacteriaceae, Acinetobacter spp . and P . aeruginosa when 1998 results were compared with those obtained in 1997 . The overall rank order of activity of the six beta-lactams tested in 1998 versus all clinical isolates was imipenem (93.2% susceptible) > cefoperazone/sulbactam (84.1%) > cefepime (80.9%) > ceftazidime (70.7%) > aztreonam (65.7%) > cefotaxime (65.6%) . In contrast, the rank order of these same agents tested against a similar collection of Colombian isolates in 1997 was imipenem (96.6% susceptible) > cefepime (93.6%) > cefoperazone/sulbactam (90.5%) > cefotaxime (74.9%) > aztreonam (74.3%) > ceftazidime (73.2%).

J Clin Microbiol, 2000 Jan, 38(1), 40 - 3
Convenient test for screening metallo-beta-lactamase-producing gram-negative bacteria by using thiol compounds; Arakawa Y et al.; A simple disk diffusion test was constructed for detection of IMP-1-type metallo-beta-lactamase-producing gram-negative bacteria . Two Kirby-Bauer disks containing ceftazidime (CAZ) and a filter disk containing a metallo-beta-lactamase inhibitor were used in this test . Several IMP-1 inhibitors such as thiol compounds including 2-mercaptopropionic acid, heavy metal salts, and EDTA were evaluated for this test . Two CAZ disks were placed on a Mueller-Hinton agar plate on which a bacterial suspension was spread according to the method recommended by the National Committee for Clinical Laboratory Standards . The distance between the disks was kept to about 4 to 5 cm, and a filter disk containing a metallo-beta-lactamase inhibitor was placed near one of the CAZ disks within a center-to-center distance of 1.0 to 2.5 cm . For IMP-1-producing strains, the growth-inhibitory zone between the two disks expanded, while no evident change in the shape of the growth-inhibitory zone was observed for CAZ-resistant strains producing serine beta-lactamases such as AmpC or SHV-12 . As a result, 2 to 3 microliter of undiluted 2-mercaptopropionic acid or mercaptoacetic acid able to block IMP-1 activity gave the most reproducible and clearest results, and CAZ-resistant strains producing AmpC or extended-spectrum beta-lactamases were distinguishable from IMP-1 producers by this test . A similar observation was made with IMP-1-producing clinical isolates such as Serratia marcescens, Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Citrobacter freundii, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas putida, Acinetobacter spp., and Alcaligenes xylosoxidans . The specificity and sensitivity of this test were comparable to those of PCR analysis using bla(IMP)-specific primers . Therefore, this convenient test would be valuable for daily use in clinical laboratories.

Appl Environ Microbiol, 2000 Jan, 66(1), 206 - 12
Natural transformation of Acinetobacter sp . strain BD413 with cell lysates of Acinetobacter sp., Pseudomonas fluorescens, and Burkholderia cepacia in soil microcosms; Nielsen KM et al.; To elucidate the biological significance of dead bacterial cells in soil to the intra- and interspecies transfer of gene fragments by natural transformation, we have exposed the kanamycin-sensitive recipient Acinetobacter sp . strain BD413(pFG4) to lysates of the kanamycin-resistant donor bacteria Acinetobacter spp., Pseudomonas fluorescens, and Burkholderia cepacia . Detection of gene transfer was facilitated by the recombinational repair of a partially (317 bp) deleted kanamycin resistance gene in the recipient bacterium . The investigation revealed a significant potential of these DNA sources to transform Acinetobacter spp . residing both in sterile and in nonsterile silt loam soil . Heat-treated (80 degrees C, 15 min) cell lysates were capable of transforming strain BD413 after 4 days of incubation in sterile soil and for up to 8 h in nonsterile soil . Transformation efficiencies obtained in vitro and in situ with the various lysates were similar to or exceeded those obtained with conventionally purified DNA . The presence of cell debris did not inhibit transformation in soil, and the debris may protect DNA from rapid biological inactivation . Natural transformation thus provides Acinetobacter spp . with an efficient mechanism to access genetic information from different bacterial species in soil . The relatively short-term biological activity (e.g., transforming activity) of chromosomal DNA in soil contrasts the earlier reported long-term physical stability of DNA, where fractions have been found to persist for several weeks in soil . Thus, there seems to be a clear difference between the physical and the functional significance of chromosomal DNA in soil.

FEMS Microbiol Lett, 2000 Jan 1, 182(1), 73 - 6
Class I integrons containing a dhfrI trimethoprim resistance gene cassette in aquatic Acinetobacter spp; Petersen A et al.; The presence of antibiotic resistance gene cassettes in class I integrons was investigated in 24 sulfamethoxazole-resistant and -sensitive Acinetobacter isolates derived from two Danish freshwater trout farms . Integrons were detected in five isolates from one of the fish farms, and their inserts were characterised by DNA sequencing . Each isolate contained a dhfrI gene cassette encoding resistance to trimethoprim and an open reading frame orfC of unknown function identical to the content of an integron previously found in a clinical enterobacterial isolate . Among the five isolates, at least two different strains were differentiated based on phenotypic tests and randomly amplified polymorphic DNA analysis . To our knowledge, this is the first report and characterisation of an integron in environmental bacteria.

Pharmacotherapy, 1999 Sep, 19(9), 1080 - 5
Evaluation of Acinetobacter baumannii infection and colonization, and antimicrobial treatment patterns in an urban teaching hospital; Weingarten CM et al.; In 1990 there was a sudden increase in the incidence of colonization and infection due to Acinetobacter baumannii (AB) in our intensive care units (ICUs) . The isolates were multiply resistant to beta-lactam and aminoglycoside antibiotics, but remained susceptible to imipenem, amikacin, and ampicillin-sulbactam . We examined the frequency of infection and colonization with AB and the effects of increased imipenem and amikacin therapy on Pseudomonas aeruginosa . We also used disease-matched controls to determine the clinical and financial impacts of treating colonization . All patients with at least one AB isolate from January-December 1992 were identified retrospectively and classified as infected or colonized based on published Centers for Disease Control criteria; the control group was selected from a computerized medical records data base matching primary diagnostic codes (102 patients both groups) . The 102 patients yielded 140 isolates, 124 resistant AB and 16 sensitive AB . Thirty three patients were infected, 69 colonized . Mortality correlated with APACHE II scores . Patients acquired the organism approximately 2 weeks after admission; they had a mean ICU stay of 27.35 days, compared with 5.53 days for controls . Patients with positive AB cultures required significantly more use of ventilators than those with negative AB cultures . They also had significantly longer hospital stay, more bed transfers, greater duration and number of antibiotics, and higher hospital and pharmacy charges . Unnecessary treatment for colonization with either imipenem or amikacin resulted in a substantial decrease of P . aeruginosa susceptibility to each agent . The financial impact of treating colonization was significant and is a potential area for cost avoidance . Our results emphasize the need to extubate and move patients to non-ICU beds as soon as possible to decrease the risk of nosocomial infection . It also highlights the need to avoid treating colonization, thus avoiding unnecessary antibiotic therapy.

Eur J Biochem, 2000 Jan, 267(1), 3 - 10
3,4-Dihydrocoumarin hydrolase with haloperoxidase activity from Acinetobacter calcoaceticus F46; Kataoka M et al.; A novel lactonohydrolase, an enzyme that catalyzes the hydrolysis of 3,4-dihydrocoumarin, was purified 375-fold to apparent homogeneity, with a 22.7% overall recovery, from Acinetobacter calcoaceticus F46, which was isolated as a fluorene-assimilating micro-organism . The molecular mass of the native enzyme, as estimated by high-performance gel-permeation chromatography, is 56 kDa, and the subunit molecular mass is 30 kDa . The enzyme specifically hydrolyzes 3,4-dihydrocoumarin, and the Km and Vmax for 3,4-dihydrocoumarin are 0.806 mM and 4760 U.mg-1, respectively . The N-terminal and internal amino acid sequences of the enzyme show high similarity to those of bacterial non-heme haloperoxidases . The enzyme exhibits brominating activity with monochlorodimedon in the presence of H2O2 and 3, 4-dihydrocoumarin or an organic acid, such as acetate and n-butyrate.

Presse Med, 1999 Nov 27, 28 Suppl 3, 19 - 21
{Focus on Acinetobacter baumannii}; Joly-Guillou ML; RESISTANCE: Acinetobacter baumannii carbapeneme-resistance is a serious problem due to the difficulty encountered in treating patients infected with this type of multiresistant bacteria . Several teams have detailed the resistance mechanisms and the way this type of strain spreads around the world . Different factors (plasmid transmission, strain variability) suggest that this type of resistance can diffuse and tends to increase with time . A NEW STRAIN: An outbreak of 15 colonizations with Acinetobacter baumannii, a BLSE producing a type PER-1 enzyme, was described in a neurosurgery intensive care unit in Great Britain . This type of strain has been exception to data and this outbreak emphasizes the problems encountered in controlling the epidemic.

Pediatr Nephrol, 1999 Nov, 13(9), 835 - 7
Microbiological spectrum of septicemia and peritonitis in nephrotic children; Tain YL et al.; From April 1993 to December 1997, 452 admissions of 231 children with nephrotic syndrome to Chang Gung Children's Hospital were retrospectively reviewed . There were 10 episodes of sepsis and 8 episodes of peritonitis in 18 children, and 14 microorganisms were cultured . Two children died due to Streptococcus pneumoniae sepsis . Gram-positive microorganisms (n=7) and Gram-negative microorganisms (n=7) were found in equal numbers . Enterococcus (1), Streptococcus pneumoniae (4), group D streptococcus (1), and Streptococcus viridans (1) were the Gram-positive microorganisms cultured . Two of 4 cases of Streptococcus pneumoniae sepsis were penicillin resistant . Gram-negative microorganisms included Enterobacter cloacae (1), Klebsiella pneumoniae (1), Escherichia coli (2), Acinetobacter baumannii (1), Neisseria meningitidis (1), and group B salmonella (1) . The last three microorganisms have not been previously associated with nephrotic children . Vancomycin therapy to cover penicillin-resistant Streptococcus pneumoniae and a third-generation cephalosporin therapy to cover rare Gram-negative microorganisms should be considered in serious infections of nephrotic children.

Antimicrob Agents Chemother, 2000 Jan, 44(1), 196 - 9
Sequence analysis of ARI-1, a novel OXA beta-lactamase, responsible for imipenem resistance in Acinetobacter baumannii 6B92; Donald HM et al.; The sequence of the bla(ARI-1) gene from imipenem-resistant Acinetobacter baumannii 6B92 has been determined . The structural gene encodes a 273-amino-acid protein which is most related to the OXA class D beta-lactamases . The conserved S-T-F-K and K-T-G motifs were identified in the ARI-1 protein sequence, also named OXA-23, but significantly, a point mutation (Y-->F) was identified in the Y-G-N conserved motif, also known to function in the active site.

J Pak Med Assoc, 1999 Jul, 49(7), 169 - 72
Prevalent nosocomial gram negative aerobic bacilli and their antimicrobial susceptibility pattern in intensive care unit; Zafar A; OBJECTIVE: To determine the type of prevalent aerobic gram-negative bacilli and their sensitivity pattern among nosocomial isolates . DESIGN: Prospective collection of clinically significant nosocomial gram negative bacilli . SETTING: Tertiary care hospital in Karachi . METHOD: One hundred isolates were identified by standard methods and minimum inhibitory concentration was checked by epsilometer test . RESULTS: The most frequent isolates were Eschericia coli (43%) followed by Klebsiella pneumoniae (18%) Acinetobacter spp . (7%) Enterobacter spp . (7%) and Klebsiella spp . other than pneumoniae (7%) . Most of the isolates of dominant species (E . coli and Klebsiella pneumoniae) were multiresistant including third generation cephalosporins . CONCLUSION: This study indicates that most effective antibiotics imipenem and amikacin inhibited most of the isolates . Imipenem alone or amikacin in combination with one broad spectrum beta-lactam drug should be used in initial empiric therapy in any life threatening nosocomial infection.

J Microbiol Immunol Infect, 1998 Jun, 31(2), 119 - 24
Acinetobacter calcoaceticus-baumannii complex bacteremia: analysis of 82 cases; Lin SY et al.; Eighty-two cases of Acinetobacter calcoaceticus-baumannii complex bacteremia were identified during a 33-month period, from November 1993 to July 1996, at the Veterans General Hospital, Taipei . All cases were due to hospital-acquired infections, with 28 cases of polymicrobial bacteremia . Most patients had severe debilitating conditions: 26 had malignancies, 40 required stay in Intensive Care Unit and 17 had undergone major operations . The main predisposing factors included central venous catheterization, endotracheal intubation or tracheostomy, prior antibiotic therapy and prolonged hospitalization . Amikacin, tobramycin, and ceftazidime were the most effective agents in vitro against A . calcoaceticus-baumannii complex . 32 patients (39 %) died during hospitalization, 19 of the cases (23 %) directly attributed to septicemia . Factors that adversely influenced mortality included polymicrobial bacteremia, inappropriate antimicrobial therapy and prior antibiotic treatment . Of particular interest is the fact that none of the patients who did not receive appropriate antimicrobial therapy survived . Early diagnosis and appropriate antibiotic therapy are critical for improving the prognosis of A . calcoaceticus-baumannii complex bacteremia.

J Appl Microbiol, 1999 Nov, 87(5), 659 - 67
Phenotypic characterization and antibiotic resistance of Acinetobacter spp . isolated from aquatic sources; Guardabassi L et al.; A total of 99 Acinetobacter isolates from sewage, freshwater aquaculture habitats, trout intestinal contents and frozen shrimps was characterized phenotypically and antibiotic susceptibility patterns determined . One group of genomic species, including Ac . johnsonii, Ac . lwoffi and spp . 15TU, was detected in all sample types and represented the majority of the isolates (n = 54) . Isolates belonging to the Acb complex (Ac . calcoaceticus, Ac . baumannii and genomic species 3) were detected in sewage (n = 6) and frozen shrimps (n = 1), Ac . haemolyticus in frozen shrimps (n = 6) and trout intestinal contents (n = 2) and genomic species 11 in freshwater aquaculture habitats (n = 6) and trout intestinal contents (n = 1) . Acinetobacter junii (n = 5), genomic species 10 (n = 2), 14BJ (n = 8) and 16BJ (n = 4) were only isolated from sewage . Acinetobacter isolates from sewage were generally more biochemically reactive and resistant to antimicrobial agents compared with isolates from other sample types . Different strains, often belonging to different genomic species, were isolated from sites situated upstream and downstream of the discharge point of a pharmaceutical plant . This finding supported the hypothesis that the waste effluent from the pharmaceutical plant was likely to cause a change in the distribution of Acinetobacter spp . by selecting and/or introducing antibiotic-resistant strains into the recipient sewers.

J Appl Microbiol, 1999 Nov, 87(5), 649 - 58
A gene involved in quinate metabolism is specific to one DNA homology group of Xanthomonas campestris; Lee YA et al.; A gene involved in quinate metabolism was cloned from Xanthomonas campestris pv . juglandis strain C5 . The gene, qumA, located on a 4 . 2-kb KpnI-EcoRV fragment in plasmid pQM38, conferred quinate metabolic activity to X . c . pv . celebensis . Tn3-spice insertional analyses further located the qumA gene on a region of about 3.0 kb within pQM38 . Nucleotide sequencing of this 3.0-kb fragment reveals that the coding region of qumA is 2373 bp, the deduced amino acid sequence of which closely resembles a pyrrolo-quinoline quinone-dependent quinate dehydrogenase of Acinetobacter calcoaceticus . A 0.7 kb SalI-PstI fragment internal to qumA was used as a probe to hybridize against total genomic DNA from 43 pathovars of X . campestris . The fragment hybridized only to total genomic DNA from the four pathovars of DNA homology group 6, X . c . pv . celebensis, X . c . pv . corylina, X . c . pv . juglandis and X . c . pv . pruni, and from X . c . pv . carotae, which belongs to DNA homology group 5 . This 0.7 kb fragment was also used as a probe to hybridize BamHI-digested total genomic DNAs from the four pathovars of DNA homology group 6 and X . c . pv . carotae . The restriction fragment length polymorphism pattern of DNA homology group 6 was different from that of X . c . pv . carotae . The probe hybridized to a 5.7-kb BamHI fragment in all four pathovars of group 6 and to a 6.1-kb BamHI fragment in three of four pathovars . It hybridized only to a 9 . 9-kb BamHI fragment in X . c . pv . carotae . Quinate metabolism has previously been reported as a phenotypic property specific to X . campestris DNA homology group 6 . Accordingly, a combination of the quinate metabolism phenotypic test and Southern hybridization using a qumA-derived probe will be very useful in the identification of pathovars in DNA homology group 6.

Surg Neurol, 1999 Nov, 52(5), 438 - 43; discussion 443-4
Gram-negative bacillary meningitis in adult post-neurosurgical patients; Lu CH et al.; BACKGROUND: To assess the clinical features and therapeutic outcomes of gram-negative bacillary meningitis (GNBM) in adult postneurosurgical patients . METHODS: Thirty adult patients with GNBM were included in this study . Their clinical features, laboratory data, prognostic factors, and therapeutic outcome were analyzed . The patients were 22 males and 8 females, aged 17-72 years . Seven had community-acquired infections and 23 had nosocomial infections . Two patients were associated with brain abscess . RESULTS: The pathogens found in the 30 GNBM patients were Pseudomonas aeruginosa, Klebsiella species, Escherichia coli, Acinetobacter baumannii, and some rare pathogens including Citrobacter freundii, Serratia marcescens, Enterobacter cloacae, and Proteus mirabilis . Among these 30 patients, 8 patients with third-generation cephalosporin-resistant GNBM were identified since 1994; all infections were nosocomially acquired . Appropriate antibiotics were given to 22 patients . Eight patients did not receive appropriate antibiotic therapy . All eight died . The mortality rate in those treated with appropriate antibiotics was 14% . CONCLUSIONS: There has been an increase of GNBM in postneurosurgical patients in recent years . In addition, the emergence of strains resistant to third-generation cephalosporins in this specific group of patients has also been noted in recent years, and has become a great therapeutic challenge . We noted many prognostic factors in postneurosurgical patients in this study; however, appropriate antibiotic therapy and initial consciousness level are the most significant ones . Therefore, in cases of postneurosurgical patients with nosocomially acquired GNBM, the possibility of third-generation cephalosporin resistance should be strongly suspected . Early initiation of appropriate antibiotic therapy is needed in this potentially fatal disease.

Microb Ecol, 1999 Oct, 38(3), 234 - 243
Bacterial Populations in an Anthropogenically Disturbed Stream: Comparison of Different Seasons; Lemke MJ et al.; Abstract To determine the effects of environmental changes on stream bacterial populations, assemblage- and population-level measurements were compared between an anthropogenically disturbed stream and an undisturbed reference stream during different seasons . Physical and chemical variables monitored at two disturbed sites from a stream affected by multiple environmental perturbations confirmed discernibly different water quality from three reference sites: two from an adjacent, undisturbed watershed and one from the headwaters of the polluted stream . Assemblage-level variables, including total number of bacteria, colony forming units, and number of Bacteria from in situ hybridization revealed only one statistically significant difference between disturbed and undisturbed sites . Population-level changes of three bacterial species, Burkholderia cepacia, Pseudomonas putida, and Acinetobacter calcoaceticus, were determined by colony hybridization with rDNA probes . Abundance of culturable A . calcoaceticus was higher at disturbed sites in November and February; B . cepacia and P . putida did not exhibit pollution-associated responses . In contrast, in situ hybridization indicated that there was more A . calcoaceticus at the reference sites in November and April, suggesting that culturability of the species increased at disturbed sites . To determine if differences among sites were attributable to changes in water quality among the streams, three bacterial strains isolated from the disturbed stream were grown for 64 h in flasks in water from disturbed and reference sites . As observed in the stream, A . calcoaceticus numbers increased in polluted stream water after an initial lag period of approximately 24 h . Our results indicate that although assemblage-level measurements of bacterial communities did not reflect environmental differences among sites, A . calcoaceticus population sizes differed between disturbed and reference sites, suggesting that anthropogenic disturbance can alter some bacterial populations and not others.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p234.html</hea

Wiad Lek, 1999, 52(7-8), 355 - 62
{Comparative analysis of occurrence and susceptibility to gram-negative bacilli isolated from intubation tubes and tracheostomy tubes in patients at intensive care units}; Pawela K et al.; The purpose of this work was to determine the frequency of occurrence and susceptibility of Gram-negative bacilli isolated from intubation tubes and tracheotomy tubes in neonates and adults in intensive care units . Nonfermenting rods were the most often isolated from the tubes especially Pseudomonas aeruginosa from 39.2% to 45.2% of Gram-negative bacilli and Acinetobacter spp . from about 10.9% of Gram-negative bacilli . The rods of Enterobacteriaceae family were isolated too . It was found that the most frequently isolated bacteria was Escherichia coli--from 17.8% to 21.4% of Gram-negative bacilli . The other rods were isolated occasionally.

J Antimicrob Chemother, 1999 Oct, 44(4), 545 - 8
In-vitro activity of cefepime and seven other antimicrobial agents against 1518 non-fermentative Gram-negative bacilli collected from 48 Canadian health care facilities . Canadian Afermenter Study Group; Blondeau JM et al.; Non-fermentative bacilli are primarily nosocomial pathogens, and are also often resistant in vitro to a broad range of antimicrobial agents . In this large Canadian study, we collected 1466 clinical, non-repeat isolates of Pseudomonas aeruginosa, 21 of Acinetobacter spp . and 31 Stenotrophomas maltophilia . MICs of eight antibiotics were determined by the NCCLS microdilution method in a central laboratory . Tobramycin was the most active agent against P . aeruginosa (94.5% susceptible); amikacin and imipenem were the most active against Acetinobacter spp . (100%) and ceftazidime was the most active against S . maltophilia (40.6%) . Against each group of isolates, cefepime was active against 87, 86.4 and 15.6%, respectively . This in-vitro study showed that cefepime may be a useful additional agent in the treatment of infections caused by P . aeruginosa and Acinetobacter spp., but not when S . maltophilia is considered pathogenic.

Am J Infect Control, 1999 Dec, 27(6), 536 - 42
Pathophysiology of surgical site infection in total hip arthroplasty; Seibert DJ; This article is a case report of a 69-year-old man who underwent a right total hip replacement procedure and developed a surgical site infection . Areas of concern in prevention and treatment of hip arthroplasty infection are presented, focusing on the pathophysiologic process involved . A review of the patient risk factors and the pathophysiologic action potentiating risk for infection include host immunity, nutritional status, diabetes, age, use of steroids or immunosuppressive drugs, rheumatoid arthritis, and urinary tract or other infections . The case report identifies the patient's age, multiple instrumentation of the bladder resulting in bacteriuria and the reinfusion of 400 cc of autologous shed blood via cell saver, a controversial risk subject, as the primary risk factors for surgical site infection in this patient . Readmission to the hospital on day 16 after the operation was completed on identification of 2 pathogenic organisms, methicillin-resistant Staphylococcus aureus and Acinetobacter calcoaceticus bio anitratus . The infection was successfully treated with oral ciprofloxacin and intravenous administration of tobramycin, preventing progression from superficial to deep infection and preserving the prosthesis.

J Microbiol Methods, 1999 Dec, 39(1), 79 - 90
Comparison of differential plating media and two chromatography techniques for the detection of histamine production in bacteria; Actis LA et al.; The bacterial enzyme histidine decarboxylase (Hdc) catalyses the conversion of histidine into histamine . This amine is essential for the biosynthesis of iron chelators (siderophores) and is an important cause of food poisoning after consumption of fish contaminated with histamine-producing bacteria . In this work we compared different methods for detecting histamine secreted by different bacterial strains . The presence of histamine in the culture supernatant of Vibrio anguillarum, which produces Hdc and secretes the histamine-containing siderophore anguibactin, was detected by thin-layer chromatography . Similar results were obtained using the culture supernatant of the Acinetobacter baumannii 19606 prototype strain that secretes the histamine-containing siderophore acinetobactin . Conversely, histamine was not detected in the culture supernatant of an isogenic V . anguillarum Hdc mutant and the A . baumannii 8399 strain that secretes a catechol siderophore different from anguibactin and acinetobactin . These results were confirmed by capillary gas chromatography/mass spectrometry . However, all these strains tested positive for histamine secretion when cultured on differential plating media containing histidine and a pH indicator, which were specifically designed for the detection of histamine-producing bacteria . The pH increase of the medium surrounding the bacterial colonies was however drastically reduced when the histidine-containing medium was supplemented with peptone, beef extract, and glucose . The histidine-containing culture supernatants of the A . baumannii and V . anguillarum strains showed an increase of about two units of pH, turned purple upon the addition of cresol red, and contained high amounts of ammonia . Escherichia coli strains, which are Hdc negative and do not use histidine as a carbon, nitrogen, and energy source, gave negative results with the differential solid medium and produced only moderate amounts of ammonia when cultured in the presence of excess histidine . This study demonstrates that, although more laborious and requiring some expensive equipment, thin-layer and gas chromatography/mass spectrometry are more accurate than differential media for detecting bacterial histamine secretion . The results obtained with these analytical methods are not affected by byproducts such as ammonia, which are generated during the degradation of histidine and produce false positive results with the differential plating media.

Diagn Microbiol Infect Dis, 1999 Oct, 35(2), 153 - 8
Multicenter evaluation of the antimicrobial activity for six broad-spectrum beta-lactams in Venezuela: comparison of data from 1997 and 1998 using the Etest method . Venezuelan Antimicrobial Resistance Study Group; Pfaller MA et al.; The minimum inhibitory concentrations of six broad-spectrum beta-lactam antimicrobial agents were determined in 1998 by use of the Etest versus a total of 502 bacteria in seven Venezuelan hospital laboratories . These data were compared with results of a similar study performed in 1997 . The organisms tested included 309 recent clinical isolates of Enterobacteriaceae, 70 Pseudomonas aeruginosa, 54 Acinetobacter species, and 69 oxacillin-susceptible Staphylococcus aureus . Extended spectrum beta-lactamase production was noted among 30% of Klebsiella pneumoniae isolates . Hyperproduction of Amp C cephalosporinase producing resistance to ceftazidime and cefotaxime was observed with 10 to 37% of isolates of Enterobacter spp., Serratia spp., and Citrobacter freundii . The overall rank order of activity of the six beta-lactams tested in this study against all clinical isolates was imipenem (96.6% susceptible) > cefepime (90.4%) > piperacillin/tazobactam (85.7%) > ceftazidime (73.5%) > cefotaxime (70.5%) > piperacillin (55.0%) . These findings were very similar to those reported for 1997.

Diagn Microbiol Infect Dis, 1999 Oct, 35(2), 135 - 42
Evaluation of the in vitro antimicrobial activity of cefepime compared to other broad-spectrum beta-lactams tested against recent clinical isolates from 10 Chinese hospitals . Chinese Antimicrobial Resistance Study Group; Xu Y et al.; A surveillance study was initiated in China in 1998 in which 10 medical centers participated . The susceptibility profiles of 996 commonly occurring pathogens belonging to 10 different species groups were tested by the Etest (AB BIODISK, Solna, Sweden) against six broad-spectrum beta-lactam antimicrobial agents (cefepime, ceftazidime, ceftriaxone, imipenem, cefoperazone/sulbactam and piperacillin or oxacillin) . Quality control was closely monitored and cefepime- and/or imipenem-resistant Enterobacteriaceae were referred to the reference laboratory (University of Iowa College of Medicine, Iowa City, IA) for confirmation . The isolates of Citrobacter spp . and Enterobacter spp . were generally inhibited by imipenem (100% susceptible) and cefepime (89-94%), but were more resistant to the other drugs tested (< or = 74% susceptible) . The indole-positive Proteus spp . and Serratia spp . isolates were > 94% susceptible to all tested beta-lactams except piperacillin . Organisms capable of producing extended spectrum beta-lactamases (ESBLs), which included Klebsiella spp . and Escherichia coli, were most susceptible to imipenem (100%) and cefepime (> 90%) . Among the non-enteric Gram-negative bacilli, all drugs were marginally active against Pseudomonas aeruginosa (MIC90s, 32-> 256 ug/mL) and the Acinetobacter spp . were rather resistant to all the compounds, except imipenem (96% susceptible) . All strains of Staphylococcus spp . were susceptible to the tested antimicrobials except for ceftazidime, which had a low potency (MIC90, 12-16 micrograms/mL) against Chinese isolates with MICs that fell into the intermediate category . Cefepime, the fourth-generation cephalosporin, showed a very broad spectrum of activity against Gram-negative pathogens as well as oxacillin-susceptible Staphylococcus spp . that was comparable with imipenem (widest spectrum) and superior to the other tested beta-lactams overall . Continued monitoring of clinical strains in China seems necessary to guide chemotherapy.

Diagn Microbiol Infect Dis, 1999 Oct, 35(2), 93 - 9
Reassessment of the routine anaerobic culture and incubation time in the BacT/Alert FAN blood culture bottles; Cornish N et al.; A total of 9,130 blood cultures were collected from adult patients with suspected bloodstream infections . The recommended 20 mL sample of blood was divided equally between the aerobic and anaerobic FAN bottles and monitored in the BacT/Alert Microbial Detection System for a total of 5 days . There were 757 clinically significant positive culture pairs from 291 patients . Significant differences were found with greater recovery of Pseudomonas aeruginosa (p < 0.001), Acinetobacter spp . (p = 0.002), coagulase-negative staphylococci other than Staphylococcus epidermidis (p = 0.002), and Candida spp . (p < 0.001) from the aerobic bottle and greater recovery of anaerobic bacteria (p < 0.001) from the anaerobic bottle . Significantly more episodes of P . aeruginosa bacteremia (p < 0.003) and candidemia (p < 0.001) were detected by the aerobic FAN bottle and significantly more episodes of anaerobic bacteremia (p < 0.001) were detected by the anaerobic FAN bottle (Table 2) . No other significant differences between systems in their detection of bacteremias were noted . Anaerobic bacteremias were encountered in diverse and often unpredictable clinical settings . All clinically significant episodes of bloodstream infection were detected within 4 days of incubation of their cultures . We conclude routine, rather than selective, use of the anaerobic FAN bottle in the blood culture set and a 4-day incubation of blood cultures in the BacT/Alert aerobic and anaerobic FAN bottles is an appropriate routine procedure.

Rev Esp Quimioter, 1999 Jun, 12(2), 140 - 3
{In vitro activity of beta-lactam agents and beta-lactamase inhibitors in clinical isolates of Acinetobacter baumannii}; Lopez-Hernandez S et al.; Acinetobacter is a Gram-negative coccobacillus frequently associated with nosocomial infections, especially pneumonia in patients using mechanical ventilators in ICUs . Many of the clinical isolates of Acinetobacter baumannii are now resistant to most antibiotics, including the betalactams, making these infections difficult to treat . We compared the in vitro activity of betalactam agents (ampicillin, piperacillin and ticarcillin), betalactamase inhibitors (clavulanic acid, sulbactam and tazobactam) alone and in combination with betalactam agents (amoxicillin-clavulanic acid, ampicillin-sulbactam, piperacillin-tazobactam and ticarcillin-clavulanic) against 156 clinical isolates of A . baumannii using an agar dilution method . In general, we observed a low susceptibility to the betalactam agents tested (ampicillin: 1.9% susceptibility; piperacillin: 10.2%; ticarcillin: 19.8%) . We did not observe a significant reduction of the MIC in the combination of betalactam agents and betalactamase inhibitors; only ampicillin/sulbactam showed a high antimicrobial activity (84.6% compared to 14.1%, 37.8% and 33.9% for amoxicillin-clavulanic acid, piperacillin-tazobactam and ticarcillin-clavulanic acid, respectively) . Sulbactam was the only betalactamase inhibitor which showed good in vitro activity, with a low MIC(50) and MIC(90) (8 and 32 mg/l, respectively) similar to ampicillin/sulbactam (2 and 16 mg/l, respectively) . Sulbactam could be a good therapeutic alternative for the treatment of multiresistant A . baumannii infections.

Eur J Biochem, 1999 Dec, 266(2), 683 - 90
Functional evaluation of the genes involved in malonate decarboxylation by Acinetobacter calcoaceticus; Koo JH et al.; The genomic locus containing the potential repressor gene mdcY (inactivated by a putative IS3 element) and the mdcLMACDEGBH genes from Acinetobacter calcoaceticus was cloned and sequenced . In order to evaluate the biochemical function of the protein components, the genes were expressed independently and their activities predicted by database analysis . The mdcA gene product, the alpha subunit, was found to be malonate/acetyl-CoA transferase and the mdcD gene product, the beta subunit, was found to be malonyl-CoA decarboxylase . The mdcE gene product, the gamma subunit, may play a role in subunit interaction to form a stable complex or as a codecarboxylase . The mdcC gene product, the delta subunit, was an acyl-carrier protein, which has a unique CoA-like prosthetic group . Various combinations of malonate decarboxylase subunits allowed us to estimate their contribution to malonyl-CoA decarboxylase activity . The prosthetic group was identified as carboxymethylated 2'-(5"-phosphoribosyl)-3'-dephospho-CoA by mass spectrometry . The mdcH gene product was determined to have malonyl-CoA/dephospho-CoA acyltransferase activity . Using database analysis mdcLM, mdcG, mdcB and mdcI were estimated to be the genes for a malonate transporter, a holo-acyl carrier synthase, protein for the formation of precursor of the prosthetic group and a regulatory protein, respectively . From the data shown above we propose a metabolic pathway for malonate in A . calcoaceticus.

Infect Immun, 1999 Dec, 67(12), 6591 - 5
Autoantibodies to brain components and antibodies to Acinetobacter calcoaceticus are present in bovine spongiform encephalopathy; Tiwana H et al.; Bovine spongiform encephalopathy (BSE) is a neurological disorder, predominantly of British cattle, which belongs to the group of transmissible spongiform encephalopathies together with Creutzfeldt-Jakob disease (CJD), kuru, and scrapie . Autoantibodies to brain neurofilaments have been previously described in patients with CJD and kuru and in sheep affected by scrapie . Spongiform-like changes have also been observed in chronic experimental allergic encephalomyelitis, at least in rabbits and guinea pigs, and in these conditions autoantibodies to myelin occur . We report here that animals with BSE have elevated levels of immunoglobulin A autoantibodies to brain components, i.e., neurofilaments (P < 0.001) and myelin (P < 0.001), as well as to Acinetobacter calcoaceticus (P < 0.001), saprophytic microbes found in soil which have sequences cross-reacting with bovine neurofilaments and myelin, but there were no antibody elevations against Agrobacterium tumefaciens or Escherichia coli . The relevance of such mucosal autoantibodies or antibacterial antibodies to the pathology of BSE and its possible link to prions requires further evaluation.

Curr Microbiol, 2000 Jan, 40(1), 34 - 9
4-Hydroxybenzoate uptake in an isolated soil Acinetobacter sp; Allende JL et al.; The isolated soil bacteria Acinetobacter strain BEM2 is able to utilize some xenobiotic aromatic compounds as a carbon source . In this study the metabolism of 4-hydroxybenzoate (4-HBA) by strain BEM2 was characterized . Degradation involved a meta-cleavage pathway yielding 3,4-dihydroxybenzoate (3,4-DHBA) as an intermediate and CO(2) as the principal product from the C atoms in the aromatic ring . 4-HBA uptake was studied, and the kinetic parameters were determined . The uptake was shown to be directly coupled to ATP hydrolysis and its synthesis, according to the Mitchell chemiosmotic hypothesis.

Burns, 1999 Nov, 25(7), 640 - 4
Rifampicin as an adjunct to vancomycin therapy in MRSA septicaemia in burns; Gang RK et al.; Rifampicin has been successfully used as an adjunct to vancomycin therapy in several clinical conditions of MRSA infections such as endocarditis, ventriculoperitoneal shunts and septicaemia . However, very little information is available in the literature regarding its use in MRSA septicaemia in burns . The present prospective study was conducted to evaluate the efficacy of rifampicin as an adjunct therapy in burn cases with MRSA septicaemia not responding well to vancomycin . Fourteen out of 36 MRSA septicaemia patients with burns who either did not or only partially responded to therapeutic doses of vancomycin within 5-6 days were treated with rifampicin as an adjunct therapy (600 mg, i.v., o.d) for 5 days during the study period between January 1995 to December 1998 . All the patients had burns due to flame and the TBSA varied between 20-90% with a mean of 64% . Eleven patients had deep and three had mixed burns . MRSA septicaemic episodes usually followed 2 3 days of detection of the organism in burn wounds . All the isolates were sensitive to vancomycin with an MIC of < or = 1.0 mg/L and were treated with vancomycin, (500 mg, i.v., 6 hourly) . The serum vancomycin levels in all the patients were within the therapeutic range . However, blood cultures still remained positive even after 5-6 days of therapy . Institution of rifampicin, as an adjunct to vancomycin therapy to which the MRSA isolates were susceptible, showed a dramatic clinical response and survival of grafts . Thirteen patients survived and one died who had 70% deep burns and blood cultures revealed a multiresistant Acinetobacter in addition to MRSA . The present study thus confirms the efficacy of clinical use of rifampicin as an adjunct in vancomycin nonresponding cases of MRSA septicaemia in burns.

New Microbiol, 1999 Oct, 22(4), 357 - 63
Psychrotrophic bacteria from a coastal station in the Ross sea (Terra Nova Bay, Antarctica); Bruni V et al.; Seawater samples were collected from a fixed, coastal station in the Terra Nova Bay at different depths during the Xth Oceanographic Cruise in the 1994-95 Antarctic summer . Picoplanktonic abundance, estimated by direct counts in epifluorescence microscopy, ranged from 2.2 x 10(7) to 1.6 x 10(8) cells.l-1 . The heterotrophic bacterial densities, evaluated on Marine Agar 2216 (Difco) after incubation at +4 degrees C for 21 days, ranged from 2 x 10(3) to 4.5 x 10(6) CFU.l-1 . The qualitative composition of the heterotrophic bacterial community was studied on 64 morphological and biochemical characters of the 125 strains isolated . Heterotrophic, psychrotrophic isolates were tentatively identified at genus level as Pseudomonas, Vibrio, Acinetobacter, and Flavobacterium/Cytophaga . In order to compare the characteristics of the isolates with those previously studied during 1989/90, the synthetical indices of the structure and the metabolic potentiality of the heterotrophic bacterial community were processed . Results showed that the bacterial community was metabolically more active and more homogenous than that previously studied.

Acta Trop, 1999 Oct 15, 73(3), 217 - 24
Bacteriological studies of blood, tissue fluid, lymph and lymph nodes in patients with acute dermatolymphangioadenitis (DLA) in course of 'filarial' lymphedema; Olszewski WL et al.; Filarial lymphedema is complicated by frequent episodes of dermatolymphangioadenitis (DLA) . Severe systemic symptoms during attacks of DLA resemble those of septicemia . The question we asked was whether bacterial isolates can be found in the peripheral blood of patients during the episodes of DLA . Out of 100 patients referred to us with 'filarial' lymphedema 14 displayed acute and five subacute symptoms of DLA . All were on admission blood microfilariae negative but had a positive test in the past . Blood bacterial isolates were found in nine cases, four acute (21%) and five subacute (26%) . In 10 acute cases blood cultures were found negative . Six blood isolates belonged to Bacilli, four to Cocci and one was Sarcina . To identify the sites of origin of bacterial dissemination, swabs taken from the calf skin biopsy wounds and tissue fluid, lymph and lymph node specimens were cultured . Swabs from the calf skin biopsy wound contained isolates in nine (47%) cases . They were Bacilli in nine, Cocci in three, Acinetobacter and Erwinia in two cases . Tissue fluid was collected from 10 patients and contained Bacilli in four (40%) and Staphylococci in three (30%) . Lymph was drained in four patients and contained isolates in all samples (100%) . They were Staphylococcus epidermis, xylosus and aureus, Acinetobacter, Bacillus subtilis and Sarcina . Three lymph nodes were biopsied and contained Staphylococcus chromogenes, xylosus, Enterococcus and Bacillus cereus . In six cases the same phenotypically defined species of bacteria were found in blood and limb tissues or fluids . In the 'control' group of patients with lymphedema without acute or subacute changes all blood cultures were negative . Interestingly, swabs from biopsy wound of these patients contained isolates in 80%, tissue fluid in 68%, lymph in 70% and lymph nodes in 58% of cases . In healthy controls, tissue fluid did not contain bacteria, and lymph isolates were found only in 12% of cases . This study demonstrates that patients with acute episodes of DLA reveal bacteremia in a high percentage of cases . Diversity of blood and tissue bacterial isolates in these patients points to a breakdown of the skin immune barrier in lymphedema and subsequently indiscriminate bacterial colonization of deep tissues and spread to an blood circulation.

Appl Environ Microbiol, 1999 Nov, 65(11), 5158 - 62
Identification of a transcriptional activator (ChnR) and a 6-oxohexanoate dehydrogenase (ChnE) in the cyclohexanol catabolic pathway in Acinetobacter sp . Strain NCIMB 9871 and localization of the genes that encode them; Iwaki H et al.; We identified chnR, a gene encoding an AraC-XylS type of transcriptional activator that regulates the expression of chnB, the structural gene for cyclohexanone monooxygenase (CHMO) in Acinetobacter sp . strain NCIMB 9871 . The gene sequence of chnE, which encodes an NADP(+)-linked 6-oxohexanoate dehydrogenase, the enzyme catalyzing the fifth step of cyclohexanol degradation, was also determined . The gene arrangement is chnB-chnE-chnR . The predicted molecular masses of the three polypeptides were verified by radiolabeling by using the T7 expression system . Inducible expression of cloned chnB in Escherichia coli depended upon the presence of chnR . A transcriptional chnB::lacZ fusion experiment revealed that cyclohexanone induces chnB expression in E . coli, in which a 22-fold increase in activity was observed.

Microbiology, 1999 Oct, 145 ( Pt 10), 2931 - 7
Regulation of polyphosphate kinase gene expression in Acinetobacter baumannii 252; Gavigan JA et al.; A strain of Acinetobacter baumannii cultured in butyric acid media was found to take up phosphate following a period of phosphate release . PCR was used to clone the polyphosphate kinase (ppk) gene from the strain . The promoter for the ppk gene was functional in the heterologous Escherichia coli host . Using RT-PCR, transcription of the ppk gene was found to be regulated by phosphate concentration.

Pediatr Infect Dis J, 1999 Oct, 18(10 Suppl), S50 - 5
Bacterial and viral etiology of serious infections in very young Filipino infants; Gatchalian SR et al.; OBJECTIVE: Pneumonia, meningitis and other serious infections are leading causes of death in developing countries . As part of a multicenter study we aimed to determine the etiology of pneumonia, meningitis and other serious infections in a cohort of Filipino infants ages 90 days or younger . METHOD: During a 2-year period, 2053 infants age 90 days or younger presenting to 1 of 3 Manila community hospitals were screened; 873 had signs or symptoms suggestive of an infectious illness, and 608 were judged to have clinical features suggestive of severe infection and had laboratory workup including blood for culture and white blood cell count, nasopharyngeal aspirate for virology, cerebrospinal fluid culture when indicated and chest radiograph . Chest radiographs were read independently by 3 radiologists without knowledge of clinical findings . RESULTS: Of the 873 enrolled infants, 81 died (91%) . After exclusion of presumed contaminants, positive bacterial culture from blood and/or cerebrospinal fluid was obtained in 35 infants (5.8%; 95% confidence interval 4%, 8%), 9 of whom died . The organisms responsible for meningitis were Acinetobacter spp . (4), Streptococcus pneumoniae (2), Escherichia coli (2), Enterobacter spp . (1), Pseudomonas aeruginosa (1), Haemophilus influenzae (1) and Staphylococcus aureus (1); those responsible for the other clinical diagnoses were Salmonella spp . (6), Enterobacter spp . (3), Streptococcus pyogenes (3), other Gram-negative organisms (8), S . pneumoniae (1) and Staphylococcus aureus (2) . In 685 infants examined for viral causes of their illness, 223 viruses were isolated from 219 infants (32%; 95% confidence interval 28%, 36%) . Enteroviruses were the most common potential pathogens identified (22% of infants studied), followed by respiratory syncytial virus (17%), rhinovirus (10%) and adenovirus (4%) . Concomitant virus identification occurred in 10 of those with positive bacterial culture (29%; 95% confidence interval, 15%, 46%), with enterovirus being found in 7 of these cases . CONCLUSION: Many young Filipino infants with life-threatening illness were evaluated in this study . Thirty-five had infections attributable to bacteria, with Salmonella spp . being the most common, followed by Gram-negative organisms . Pneumococcus was an unusual cause.

Diagn Microbiol Infect Dis, 1999 Sep, 35(1), 45 - 53
In vitro susceptibility to pexiganan of bacteria isolated from infected diabetic foot ulcers; Ge Y et al.; During two clinical trials involving the treatment of 835 outpatients with infected diabetic foot ulcers, 2515 bacterial isolates, including 2337 aerobes and 178 anaerobes, were grown from cultures of the ulcers . The in vitro susceptibility of these isolates was determined to pexiganan, a peptide anti-infective evaluated in these clinical trials, and to other classes of antibiotics . Pexiganan demonstrated broad spectrum antimicrobial activity against Gram-positive and Gram-negative aerobes and anaerobes . The MIC90 values for the most common species among 1735 Gram-positive aerobes isolated, such as Staphylococcus aureus, coagulase-negative staphylococci, Group A streptococci, and Group B streptococci, were 16 micrograms/mL or less . Of 602 Gram-negative aerobes tested, the MIC90 values for pexiganan were 16 micrograms/mL or less for Acinetobacter, Pseudomonas, Stenotrophomonas, Citrobacter, Enterobacter, Escherichia, Klebsiella, and Flavobacterium species . Pexiganan had a MIC90 of 4 to 16 micrograms/mL against the anaerobic isolates of Bacteroides, Peptostreptococcus, Clostridium, and Prevotella species . Importantly, pexiganan did not exhibit cross-resistance with other commonly used antibiotics, including beta-lactams, quinolones, macrolides, and lincosamides . The broad spectrum in vitro antimicrobial activity of pexiganan against clinical isolates from infected diabetic foot ulcers supports its potential as a local therapy for infected diabetic foot ulcers.

Int J Antimicrob Agents, 1999 Aug, 12 Suppl 1, S9 - 14; discussion S26-7
In vitro efficacy of beta-lactam/beta-lactamase inhibitor combinations against bacteria involved in mixed infections; Finegold SM; Mixed infections are usually caused by a relatively limited range of bacteria, with the anaerobes and opportunistic pathogens contributing to their severity . In order to make the best therapeutic choice for a patient with a life-threatening infection, which is probably of mixed etiology, clinicians must be aware of the organisms that are likely to be involved, and the fact that most of them will produce beta-lactamase . Of the options available for empiric therapy, the beta-lactam/beta-lactamase inhibitor combinations represent a good choice . Their antibacterial spectra include both aerobic and anaerobic pathogens . Five combinations are available in clinical practice: ampicillin-sulbactam, piperacillin-tazobactam, ticarcillin-clavulanic acid, amoxicillin-clavulanic acid, and cefoperazone-sulbactam . More strains of clinically important anaerobic bacteria are susceptible to ampicillin-sulbactam than to either piperacillin-tazobactam or ticarcillin-clavulanic acid, which are also available widely and suitable for more life-threatening infections . In addition, sulbactam itself has the highest intrinsic activity of the beta-lactamase inhibitors against the opportunistic pathogen, Acinetobacter baumannii . Thus, ampicillin-sulbactam could be considered a drug of choice for the empirical treatment of mixed infections where there is a reasonable possibility of the presence of A . baumannii.

Clin Infect Dis, 1999 Nov, 29(5), 1133 - 7
Seasonal variation of Acinetobacter infections: 1987-1996 . Nosocomial Infections Surveillance System; McDonald LC et al.; To determine whether nosocomial infections due to Acinetobacter species have increased over the past 10 years and whether infections continue to have a pronounced seasonal variation, we analyzed infections reported by hospitals in the National Nosocomial Infections Surveillance System that performed adult and pediatric intensive care unit surveillance from 1987 through 1996 . Overall, 3447 nosocomial acinetobacter infections were reported during 5,596, 156 patient-days . There was a yearly median of 7.2 infections (range, 5.0-10.5) per 10,000 patient-days and a downward trend in the rate of acinetobacter infections overall (P<.05) and of 2 major types of infection (P<.05): bloodstream infections (yearly median, 1.6 per 10, 000 central venous catheter-days; range, 1.3-2.9) and pneumonia (yearly median, 7.6 per 10,000 ventilator-days; range, 6.5-12.0) . Throughout this period, average rates were significantly higher during July-October than during November-June for acinetobacter infections overall (8.0 vs . 5.2; P<.01) and for bloodstream infections (2.0 vs . 1.2; P<.01) and pneumonia (9.7 vs . 6.6; P<.01).

Carbohydr Res, 1999 Jun 30, 319(1-4), 204 - 8
Structure of the O-specific polysaccharide for Acinetobacter baumannii serogroup O1; Galbraith L et al.; A polymeric fraction containing D-galactose, N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine was isolated from the lipopolysaccharide produced by the reference strain for Acinetobacter baumannii serogroup O1 . By means of NMR spectroscopy, methylation analysis, and chemical degradation, the repeating unit of the polymer was identified as a branched trisaccharide of the following structure . {formula: see text}.

Proc Natl Acad Sci U S A, 1999 Oct 12, 96(21), 11787 - 91
Active-site structure of the soluble quinoprotein glucose dehydrogenase complexed with methylhydrazine: a covalent cofactor-inhibitor complex; Oubrie A et al.; Soluble glucose dehydrogenase (s-GDH) from the bacterium Acinetobacter calcoaceticus is a classical quinoprotein . It requires the cofactor pyrroloquinoline quinone (PQQ) to catalyze the oxidation of glucose to gluconolactone . The precise catalytic role of PQQ in s-GDH and several other PQQ-dependent enzymes has remained controversial because of the absence of comprehensive structural data . We have determined the crystal structure of a ternary complex of s-GDH with PQQ and methylhydrazine, a competitive inhibitor of the enzyme . This complex, refined at 1.5-A resolution to an R factor of 16.7%, affords a detailed view of a cofactor-binding site of s-GDH . Moreover, it presents the first direct observation of covalent PQQ adduct in the active-site of a PQQ-dependent enzyme, thereby confirming previous evidence that the C5 carbonyl group of the cofactor is the most reactive moiety of PQQ.

Eur J Clin Microbiol Infect Dis, 1999 Aug, 18(8), 595 - 8
Molecular and antibiogram relationships of Acinetobacter isolates from two contrasting hospitals in the United Kingdom and South Africa; Webster CA et al.; The aim of this study was to compare the molecular relationships and antibiograms of nosocomial isolates of Acinetobacter spp . from two acute-care hospitals in Nottingham, UK, and Soweto, South Africa, with different hospital infection control problems and procedures . In contrast to Nottingham, where randomly amplified polymorphic DNA fingerprinting demonstrated that a single multiresistant strain of Acinetobacter baumannii has predominated in the hospital intensive care unit over an 11-year period, the Soweto isolates formed a heterogeneous group of unrelated molecular clusters of different antibiograms, with numerous different strains of Acinetobacter baumannii, Acinetobacter sp . 3 and Acinetobacter sp . 13TU apparently being endemic throughout the Soweto hospital . The contrasting results illustrate the need to maintain exemplary infection control procedures in hospitals where high standards have been achieved and warn of what might result if such measures are diminished.

J Bacteriol, 1999 Oct, 181(20), 6478 - 87
Substitution, insertion, deletion, suppression, and altered substrate specificity in functional protocatechuate 3,4-dioxygenases; D'Argenio DA et al.; Protocatechuate 3,4-dioxygenase is a member of a family of bacterial enzymes that cleave the aromatic rings of their substrates between two adjacent hydroxyl groups, a key reaction in microbial metabolism of varied environmental chemicals . In an appropriate genetic background, it is possible to select for Acinetobacter strains containing spontaneous mutations blocking expression of pcaH or -G, genes encoding the alpha and beta subunits of protocatechuate 3, 4-dioxygenase . The crystal structure of the Acinetobacter oxygenase has been determined, and this knowledge affords us the opportunity to understand how mutations alter function in the enzyme . An earlier investigation had shown that a large fraction of spontaneous mutations inactivating Acinetobacter protocatechuate oxygenase are either insertions or large deletions . Therefore, the prior procedure of mutant selection was modified to isolate Acinetobacter strains in which mutations within pcaH or -G cause a heat-sensitive phenotype . These mutations affected residues distributed throughout the linear amino acid sequences of PcaH and PcaG and impaired the dioxygenase to various degrees . Four of 16 mutants had insertions or deletions in the enzyme ranging in size from 1 to 10 amino acid residues, highlighting areas of the protein where large structural changes can be tolerated . To further understand how protein structure influences function, we isolated strains in which the phenotypes of three different deletion mutations in pcaH or -G were suppressed either by a spontaneous mutation or by a PCR-generated random mutation introduced into the Acinetobacter chromosome by natural transformation . The latter procedure was also used to identify a single amino acid substitution in PcaG that conferred activity towards catechol sufficient for growth with benzoate in a strain in which catechol 1,2-dioxygenase was inactivated.

Arzneimittelforschung, 1999 Sep, 49(9), 770 - 2
Cytotoxic activity of Acinetobacter baumannii after treatment with aminoglycosides; Hostacka A et al.; The effect of three aminoglycoside antibiotics--netilmicin (CAS 56391-57-2), gentamicin (CAS 1403-66-3) and amikacin (CAS 37517-28-5)--at subinhibitory concentrations (sub-MICs; 1/4 or 1/16 of the MICs) on the cytotoxic activity of Acinetobacter baumannii was studied . The cytotoxic factor was manifested by reduction of the number of isolated rat lung type II cells evaluated by alkaline phosphatase determination . All aminoglycosides at both concentrations studied (with the exception of 1/4 of the MIC of amikacin) did not modify cytotoxic activity of A . baumannii . This activity was partially inhibited only after treatment with amikacin at 1/4 of the MIC . In this case the number of type II cells after incubation with antibiotic treated A . baumannii was higher (71%) as compared to the number of type II cells cultured with untreated A . baumannii (47%).

Biotechnol Prog, 1999 Oct 1, 15(5), 919 - 922
Lipase Production by Acinetobacter radioresistens in the Presence of a Nonwoven Fabric; Shen CC et al.; Lipase production by Acinetobacter radioresistens was performed in a 2-L tank fermentor equipped with a nonwoven fabric, which was made of nylon 6 fiber and coated with a hydrophobic acrylic resin . The fermentation medium contained 2% (v/v) n-hexadecane as the carbon source . The use of the nonwoven fabric was intended for the dispersion of hydrocarbons; thus, the contact surface for the cells to assimilate n-hexadecane can be increased without using emulsifiers . The formation of lipase was found to be growth-associated when the cells grew on n-hexadecane . The use of the nonwoven fabric increased the lipase yield by 130% . Further supplementation of 0.1% (v/v) olive oil to the medium could markedly shorten the fermentation time, and thus increase the volumetric productivity . The use of the nonwoven fabric offered two additional advantages in the lipase fermentation: ease of foam control and favorable partition of lipase in the aqueous phase.

Appl Environ Microbiol, 1999 Oct, 65(10), 4568 - 74
Identification and characterization of ComE and ComF, two novel pilin-like competence factors involved in natural transformation of Acinetobacter sp . strain BD413; Busch S et al.; Although the high level of competence for natural transformation of Acinetobacter sp . strain BD413 has been the subject of numerous studies, only two competence genes, comC and comP, have been identified to date . By chromosomal walking analysis we found two overlapping open reading frames, designated comE and comF, starting 61 bp downstream of comC . comE and comF are expressed as stable proteins in Escherichia coli, thus proving that they are indeed coding regions, but expression was successful only with 5'-deleted genes . ComE and ComF are similar to pilins and pilin-like components . Both genes were mutated, and the phenotypes of the mutants were analyzed . Natural transformation in comF mutants is 1,000-fold reduced, whereas comE mutants exhibit 10-fold-reduced transformation frequencies . This is clear evidence that comE and comF are involved in natural transformation . However, ComE and ComF are specific for DNA translocation, since comE and comF defects affected neither piliation nor lipase secretion . These results suggest that the type IV pili, the general protein secretion pathway, and the DNA translocation machinery in Acinetobacter sp . strain BD413 are evolutionary related but functionally distinct systems.

Antimicrob Agents Chemother, 1999 Oct, 43(10), 2538 - 41
Reconstruction of an active integron recombination site after integration of a gene cassette at a secondary site; Segal H et al.; As the site of insertion of the aadB gene cassette on pRAY, from a clinical isolate of Acinetobacter, is almost identical to the preferred site on integrons, the composite 59-base element (59-BE) associated with this cassette is potentially recombinationally active . By using a conduction assay to quantitate site activity, the 59-BE was recognized by integrase with high frequency, indicating that the composite site is recombinationally active.

Perit Dial Int, 1999 Jul-Aug, 19(4), 357 - 60
Once-daily intraperitoneal gentamicin is effective therapy for gram-negative CAPD peritonitis; Lye WC et al.; OBJECTIVE: To report our 3-year experience with the use of once-daily intraperitoneal (IP) gentamicin in the treatment of gram-negative continuous ambulatory peritoneal dialysis (CAPD) peritonitis . DESIGN: A prospective cohort study in prevalent CAPD patients . SETTING: A tertiary care institution . PATIENTS: All CAPD patients who presented with new episodes of peritonitis were studied . At presentation with peritonitis, IP vancomycin and gentamicin were administered as empirical therapy . IP gentamicin was given at a single daily dose of 40 mg/2 L in the overnight bag . The antimicrobial agents were reviewed when the culture results became available . Intraperitoneal ceftazidime was added for the treatment of pseudomonas peritonitis . MAIN OUTCOME MEASURES: Results of microbiological cultures and clinical outcomes of peritonitis were analyzed . RESULTS: Over a 36-month period, 190 episodes of peritonitis were recorded, of which 62/190 episodes (32.6%) isolated gram-negative organisms . The gram-negative organisms isolated were Escherichia coli, 15/62 episodes (24.1%); Pseudomonas aeruginosa, 12/62 episodes (19.4%); Acinetobacter spp, 12/62 episodes (19.4%); Klebsiella spp, 10/62 episodes (16.1%); and others, 13/62 episodes (21.0%) . The overall treatment success rate was 66.1% . The treatment success rates were 74.0% if pseudomonas infections were excluded, 76.1% if gentamicin-resistant pathogens were excluded, and 80.5% if both pseudomonas infections and gentamicin-resistant pathogens were excluded . CONCLUSIONS: Once-daily IP gentamicin appears to be effective in the treatment of gram-negative CAPD peritonitis.

Crit Care Med, 1999 Sep, 27(9), 1794 - 9
Mortality and the increase in length of stay attributable to the acquisition of Acinetobacter in critically ill patients; Garcia-Garmendia JL et al.; OBJECTIVE: To determine the impact of Acinetobacter baumannii (AB) acquisition in intensive care unit (ICU) patients on mortality and length of stay (LOS) . DESIGN: Pairwise matched 1:1 case-control study . SETTING: Medical-surgical ICU in a tertiary health care institution . PATIENTS: During 16 months, all patients admitted to the ICU were eligible . Case patients were defined as every patient with an AB isolation 48 hrs after ICU admission . Control patients were retrospectively selected from ICU patients without any AB isolation, according to seven matching variables . MEASUREMENTS AND MAIN RESULTS: Attributable mortality and excess LOS in the ICU were measured . Eighty-seven patients were included, with 75 pairs successfully matched . Infection was defined in 48 patients (23 respiratory) . The attributable mortality rate for AB acquisition was 30% (49% vs.19%) (95% confidence interval {CI} = 23%, 37%): 43% (CI = 34%, 52%) in patients with infection (58% vs.15%) and 53% (CI = 41%, 65%) in patients with respiratory infections (70% vs.17%) . The estimated risk rates for death were 2.6 (CI = 1.6, 4.5; p < .001), 4.0 (CI = 1.9, 8.3; p < .001), and 4.0 (CI = 1.6, 10.2; p < .01), respectively . The attributable excess LOS was 13 days for both AB acquisition and infection (23 vs . 10 days; p < .001) and respiratory infections (23 vs . 10 days; p < .01) . In noninfected patients, no significant excess of mortality was found (33% vs . 26%), but LOS increased in 15 days . CONCLUSION: AB acquisition involved an excess LOS in ICU patients and increased risk of death, but the latter could be found only in patients with proven infection.

Eur J Biochem, 1999 Oct, 265(2), 549 - 55
Phenol hydroxylase from Acinetobacter radioresistens is a multicomponent enzyme . Purification and characterization of the reductase moiety; Pessione E et al.; This paper reports the isolation and characterization of phenol hydroxylase (PH) from a strain belonging to the Acinetobacter genus . An Acinetobacter radioresistens culture, grown on phenol as the only carbon and energy source, produced a multicomponent enzyme system, located in the cytoplasm and inducible by the substrate, that is responsible for phenol conversion into catechol . Because of the wide diffusion of phenol as a contaminant, the present work represents an initial step towards the biotechnological treatment of waste waters containing phenol . The reductase component of this PH system has been purified and isolated in large amounts as a single electrophoretic band . The protein contains a flavin cofactor (FAD) and an iron-sulfur cluster of the type {2Fe-2S} . The function of this reductase is to transfer reducing equivalents from NAD(P)H to the oxygenase component . In vitro, the electron acceptors can be cytochrome c as well as other molecules such as 2, 6-dichlorophenolindophenol, potassium ferricyanide, and Nitro Blue tetrazolium . The molecular mass of the reductase was determined to be 41 kDa by SDS/PAGE and 38.8 kDa by gel permeation; its isoelectric point is 5.8 . The N-terminal sequence is similar to those of the reductases from A . calcoaceticus NCIB 8250 (10/12 identity) and Pseudomonas CF600 (8/12 identity) PHs, but much less similar (2/12 identity) to that of benzoate dioxygenase reductase from A . calcoaceticus BD413 . Similarly, the internal peptide sequence of the A . radioresistens PH reductase displays a good level of identity (9/10) with both A . calcoaceticus NCIB 8250 and Pseudomonas CF600 PH reductase internal peptide sequences but a poorer similarity (3/10) to the internal peptide sequence of benzoate dioxygenase reductase from A . calcoaceticus BD413.

Intensive Care Med, 1999 Sep, 25(9), 1010 - 2
Influences of alternate therapy protocol and continuous infectious disease consultation on antibiotic susceptibility in ICU; Akalin H et al.; In this study, the effects of alternate use of imipenem and cefoperazone/sulbactam(CFP/Sul) on antibiotic resistance in the intensive care unit (ICU) were investigated . Between 1 April 1993 and 1 April 1994, the infectious diseases consultant saw patients when required and there was no alternative therapy for antibiotics . For the following 2 years, the same consultant followed up each patient from admission to discharge by daily visits to the ICU and an alternative therapy protocol was initiated . The most common microorganisms were found to be Acinetobacter baumannii and Staphylococcus aureus, followed by Pseudomonas aeruginosa and Klebsiella pneumoniae, respectively, in the two periods . This study demonstrated that sensitivity rates of imipenem, ciprofloxacin and aminoglycosides were improved as a result of this protocol.

Arch Biochem Biophys, 1999 Oct 1, 370(1), 93 - 6
Stereochemical course of biotin-independent malonate decarboxylase catalysis; Handa S et al.; Malonate decarboxylases, which catalyze the conversion of malonate to acetate, can be classified into biotin-dependent and biotin-independent enzymes . In order to reveal the stereochemical course of the reactions catalyzed by the biotin-independent enzymes from Acinetobacter calcoaceticus and Pseudomonas fluorescens, a chiral substrate, malonate carrying (13)C in one carboxyl group and (3)H at one of the methylene positions, was prepared and used in the reactions catalyzed by these two enzymes . The decarboxylation of (R)-{1-(13)C(1), 2-(3)H}malonate in (2)H(2)O gave a pseudo-racemate of chiral acetate which was converted via acetyl-CoA into malate with malate synthase . From the relative proportions of the isotopomers of malate present, determined by (3)H NMR analysis, it was concluded that in the decarboxylation of malonate by these two biotin-independent enzymes COOH is replaced by H with retention of configuration . The same stereochemical outcome had been previously observed for the reaction catalyzed by the biotin-dependent malonate decarboxylase from Malonomonas rubra (J . Micklefield et al . J . Am . Chem . Soc . 117, 1153-1154, 1995) .

Int J Antimicrob Agents, 1999 Aug, 12(4), 311 - 7
Comparative activities of six different fluoroquinolones against 9,682 clinical bacterial isolates from 20 European university hospitals participating in the European SENTRY surveillance programme . The SENTRY participants group; Schmitz FJ et al.; The in-vitro activities of gatifloxacin, trovafloxacin, levofloxacin, sparfloxacin, ofloxacin, and ciprofloxacin were tested against 9,682 clinical bacterial isolates from 20 European university hospitals participating in the European SENTRY surveillance programme . Gatifloxacin and trovafloxacin exhibited the highest activities against gram-positive cocci, while levofloxacin, ofloxacin, ciprofloxacin, and gatifloxacin were the most active against Enterobacteriaceae . Ciprofloxacin and levofloxacin showed the highest antimicrobial activities against Pseudomonas spp., while gatifloxacin and trovafloxacin were the most active against Acinetobacter spp . and Stenotrophomonas maltophilia . All Haemophilus spp . and Moraxella catarrhalis isolates were fully susceptible to all quinolones tested . Overall, the new quinolones, showed improved activity against gram-positive cocci and gram-negative non-fermenters while retaining their broad-spectrum activity against gram-negative bacilli.

J Food Prot, 1999 Sep, 62(9), 1024 - 32
A data analysis of the irradiation parameter D10 for bacteria and spores under various conditions; van Gerwen SJ et al.; This paper provides approximate estimates for the irradiation parameter D10 to globally predict the effectiveness of any irradiation process . D10 is often reported to depend on many specific factors, implying that D10 cannot be estimated without exact knowledge of all factors involved . For specific questions these data can of course be useful but only if the conditions reported exactly match the specific question . Alternatively, this study determined the most relevant factors influencing D10, by quantitatively analyzing data from many references . The best first step appeared to be a classification of the data into vegetative bacteria and spores . As expected, spores were found to have significantly higher D10 values (average 2.48 kGy) than vegetative bacteria (average 0.762 kGy) . Further analyses of the vegetative bacteria confirmed the expected extreme irradiation resistance of nonpathogenic Deinococcus radiodurans (average 10.4 kGy) . Furthermore the analysis identified Enterococcus faecium, Alcaligenes spp., and several members of the Moraxella-Acinetobacter group as having very high resistance at very low temperatures (average 3.65 kGy) . After exclusion of high- and low-resistance spores and some specific conditions showing relevant high or low D10 values, the average for spores was estimated to be 2.11 kGy . For vegetative bacteria this average was estimated to be 0.420 kGy . These approximate estimates are not definite, as they depend on the data used in the analyses . It is expected that inclusion of more data will not change the estimates to a great extent . The approximate estimates are therefore useful tools in designing and evaluating irradiation processes.

J Clin Microbiol, 1999 Oct, 37(10), 3108 - 12
Application of infrequent-restriction-site PCR to clinical isolates of Acinetobacter baumannii and Serratia marcescens; Yoo JH et al.; We applied infrequent-restriction-site PCR (IRS-PCR) to the investigation of an outbreak caused by 23 isolates of Acinetobacter baumannii in an intensive care unit from November 1996 to May 1997 and a pseudoepidemic caused by 16 isolates of Serratia marcescens in a delivery room from May to September 1996 . In the epidemiologic investigation of the outbreak caused by A . baumannii, environmental sampling and screening of all health care workers revealed the same species from the Y piece of a mechanical ventilator and the hands of two health care personnel . IRS-PCR showed that all outbreak-related strains were genotypically identical and that three strains from surveillance cultures were also identical to the outbreak-related strains . In a pseudoepidemic caused by S . marcescens, IRS-PCR identified two different genotypes, and among them one genotype was predominant (15 of 16 {93.8%} isolates) . Extensive surveillance failed to find any source of S . marcescens . Validation of the result of IRS-PCR by comparison with that of field inversion gel electrophoresis (FIGE) showed that they were completely concordant . These results suggest that IRS-PCR is comparable to FIGE for molecular epidemiologic studies . In addition, IRS-PCR was less laborious and less time-consuming than FIGE . To our knowledge, this is the first report of the application of IRS-PCR to A . baumannii and S . marcescens.

Dtsch Med Wochenschr, 1999 Aug 6, 124(31-32), 919 - 24
{Nosocomial pneumonias in a neurology intensive care unit}; Heckmann JG et al.; BACKGROUND AND OBJECTIVE: Nosocomial pneumonia in patients in an intensive care unit (ICU) are a great problem as a cause of increased morbidity and mortality as well as the resulting high cost of treatment . This study was aimed at determining the incidence of nosocomial pneumonia and the risk factors for its occurrence in patients with severe neurological disease . PATIENTS AND METHODS: Between 1.1 . and 31.12.1997, 217 patients (125 men, 92 women; average age 63.4 years) were prospectively included if they were treated for more than 48 hours in the ICU of the Neurology Department of Erlangen University . The occurrence of nosocomial pneumonia (NP) was noted, using the criteria of the Center of Disease Control and Prevention (CDC) . Incidence of the diseases was related to age, sex, initial state of consciousness, type of ventilation, duration of stay in the ICU and any associated medical condition . RESULTS: NP was diagnosed in 68 patients (31.4%) . Statistically significant relative risks were male sex (2.4 fold, P < 0.01), clouded consciousness with a Glasgow coma score < 8 (6.2 fold, P < 0.001), mechanical ventilation (8.4 fold, P < 0.001), time in ICU > or = 8 days (9.3 fold, P < 0.001) and associated medical condition (3.3 fold, P < 0.005) . In 17.7% of cases no relevant pathogen was identified microbiologically . A mixed infection was present in 36.8% of cases . The most common Gram-positive organism was Staph, aureus (35.3%), the most common Gram-negative ones were Ps . aeruginosa (25%), Kl . pneumoniae and Kl . oxytoca (11.8%), E . Coli (10.3%) and Acinetobacter species (7.4%) . There was also a high rate of infection or infestation with Candida albicans or glabrata (41.2%) . NP played a clinically decisive role in the fatal course of 13 of the 47 patients who died . CONCLUSION: These data (incidence, relative risk) can, by taking into consideration various aspects of specialist and hospital hygienic practices, contribute to a continuing optimization of the prevention and treatment of disease.

Chemotherapy, 1999 Sep-Oct, 45(5), 349 - 59
A cluster of nosocomial cross-infection due to multiple antibiotic-resistant Acinetobacter baumannii: Characterization of the strain and antibiotic susceptibility studies; Traub WH et al.; A multiple antibiotic-resistant (MAR) strain of Acinetobacter baumannii caused nosocomial cross-infection among 3 patients of a surgical intensive care unit . The isolates were of identical biochemical profile (77776 S-U-) and serotype (serovar 36) and identical in terms of pulsed-field gel electrophoresis macrorestriction (SmaI, ApaI) analysis . This MAR strain was susceptible only to netilmicin, tobramycin, imipenem, meropenem, polymyxin B, and trovafloxacin . The minimal bactericidal concentrations of imipenem and meropenem were markedly higher than the corresponding minimal inhibitory concentrations against this strain . Combined fresh defibrinated human blood (65 vol%) and antimicrobial drug assays yielded the following results: polymyxin was the most rapidly bactericidally effective antibiotic in the presence of blood and in broth . Tobramycin and netilmicin were efficacious in 65 vol% blood . Imipenem was slightly more effective than meropenem in broth, whereas both carbapenems sterilized blood-containing assay tube contents . Trovafloxacin failed to achieve bactericidal activity (to 99.9% kill) in the presence of blood, presumably because this strain was resistant to ciprofloxacin and borderline susceptible to ofloxacin . Trovafloxacin combined with either imipenem or meropenem yielded an indifferent effect . However, the combination of trovafloxacin (2 microg/ml) plus tobramycin (1 microg/ml) achieved sterilization of tube contents in the presence of blood within 4 h after exposure and in broth following extended (overnight) incubation . This MAR strain of A . baumannii was high-level resistant to rifampin; thus the combination of polymyxin B plus rifampin proved indifferent.

Appl Environ Microbiol, 1999 Sep, 65(9), 3780 - 6
Polyphosphate kinase of Acinetobacter sp . strain ADP1: purification and characterization of the enzyme and its role during changes in extracellular phosphate levels; Trelstad PL et al.; Polyphosphate (polyP) is a ubiquitous biopolymer whose function and metabolism are incompletely understood . The polyphosphate kinase (PPK) of Acinetobacter sp . strain ADP1, an organism that accumulates large amounts of polyP, was purified to homogeneity and characterized . This enzyme, which adds the terminal phosphate from ATP to a growing chain of polyP, is a 79-kDa monomer . PPK is sensitive to magnesium concentrations, and optimum activity occurs in the presence of 3 mM MgCl(2) . The optimum pH was between pH 7 and 8, and significant reductions in activity occurred at lower pH values . The greatest activity occurred at 40 degrees C . The half-saturation ATP concentration for PPK was 1 mM, and the maximum PPK activity was 28 nmol of polyP monomers per microg of protein per min . PPK was the primary, although not the sole, enzyme responsible for the production of polyP in Acinetobacter sp . strain ADP1 . Under low-phosphate (P(i)) conditions, despite strong induction of the ppk gene, there was a decline in net polyP synthesis activity and there were near-zero levels of polyP in Acinetobacter sp . strain ADP1 . Once excess phosphate was added to the P(i)-starved culture, both the polyP synthesis activity and the levels of polyP rose sharply . Increases in polyP-degrading activity, which appeared to be mainly due to a polyphosphatase and not to PPK working in reverse, were detected in cultures grown under low-P(i) conditions . This activity declined when phosphate was added.

Am J Respir Crit Care Med, 1999 Sep, 160(3), 961 - 7
Cytokines IL-1beta, IL-6, and TNF-alpha enhance in vitro growth of bacteria; Meduri GU et al.; We have previously reported that in acute respiratory distress syndrome (ARDS), nonsurvivors have persistent elevation in pulmonary and circulating proinflammatory cytokine levels over time and a high rate of nosocomial infections antemortem . In these patients, none of the proven or suspected nosocomial infections caused a transient or sustained increase in plasma proinflammatory cytokine levels above preinfection values . We hypothesized that cytokines secreted by the host during ARDS may favor the growth of bacteria . We conducted an in vitro study of the growth of three bacteria clinically relevant in nosocomial infections, evaluating their in vitro response to various concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 . We found that all three bacterial species showed concentration-dependent growth enhancement when incubated with one or more tested cytokines and that blockade by specific neutralizing cytokine MoAb significantly inhibited cytokine-induced growth . When compared with control, the 6-h growth response (cfu/ml) was maximal with IL-1beta at 1,000 pg for Staphylococcus aureus (36 +/- 16 versus 377 +/- 16; p = 0.0001) and Acinetobacter spp . (317 +/- 1,147 versus 1,124 +/- 147; p = 0.002) and with IL-6 at 1,000 pg for Pseudomonas aeruginosa (99 +/- 50 versus 509 +/- 50; p = 0.009) . The effects of cytokines were seen only with fresh isolates and were lost with passage in vitro on bacteriologic medium without added cytokines . In this study we provide additional evidence for a newly described pathogenetic mechanism for bacterial proliferation in the presence of exaggerated and protracted inflammation.

J Biochem (Tokyo), 1999 Sep, 126(3), 624 - 31
Steroid monooxygenase of Rhodococcus rhodochrous: sequencing of the genomic DNA, and hyperexpression, purification, and characterization of the recombinant enzyme; Morii S et al.; Steroid monooxygenase of Rhodococcus rhodochrous is a Baeyer-Villigerase catalyzing the insertion of an oxygen atom between the C(17)- and C(20)-carbons of progesterone to produce testosterone acetate . The 5.1-kbp-long BamHI DNA fragment containing the steroid monooxygenase gene, smo, was cloned from the chromosomal DNA and sequenced . The smo gene is 1,650 nucleotides long, starts with a TTG codon, and ends with a TGA codon . The deduced amino acid sequence indicates that the enzyme protein consist of 549 amino acid residues with a molecular mass of 60,133 . Thus, the molecular mass of the holoenzyme is 60,919 . The amino acid sequence is highly homologous (41.2% identity) to that of cyclohexanone monooxygenase of Acinetobacter sp . In the upstream of the smo gene, the genes of heat shock proteins, dnaK, grpE, and dnaJ, located on the complementary strand, and the DNA-inserts of pSMO and pD1, which contains the ksdD gene, were joined at the BamHI site of the dnaJ gene . The smo gene was modified at the initiation codon to ATG and ligated with an expression vector to construct a plasmid, pSMO-EX, and introduced into Escherichia coli cells . The transformed cells hyperexpressed the steroid monooxygenase as an active and soluble protein at more than 40 times the level in R . rhodochrous cells . Purification of the recombinant monooxygenase from the E . coli cells by simplified procedures yielded about 2.3 mg of enzyme protein/g wet cells . The purified recombinant steroid monooxygenase exhibited indistinguishable molecular and catalytic properties from those of the R . rhodochrous enzyme.

Wien Klin Wochenschr, 1999 Jul 30, 111(14), 549 - 54
In vitro activity of newer broad spectrum beta-lactam antibiotics against enterobacteriaceae and non-fermenters: a report from Austrian intensive care units . Austrian Carbapenem Susceptibility Surveillance Group; Krause R et al.; We compared the in vitro activity of broad spectrum beta-lactam antibiotics against 573 gram-negative isolates (enterobacteriaceae and non-fermenters) collected between November 1996 and May 1997 from 9 laboratories serving intensive care units throughout Austria . MIC's (Minimal Inhibitory Concentration) were obtained with the E-test for meropenem, imipenem, ceftazidime, cefepime, cefpirome and piperacillin/tazobactam . Pseudomonas aeruginosa was the most frequently isolated organism (22%), followed by E . coli (19%), Klebsiella spp . (16%), and Enterobacter spp . (14%) . Acinetobacter spp., Proteus spp., Serratia spp., Stenotrophomonas maltophilia, Citrobacter spp., Morganella morganii, Burkholderia cepacia and Salmonella enteritidis were isolated less frequently . Overall meropenem, imipenem and ceftazidime were the most active compounds in vitro, inhibiting 90%, 89%, and 87% of the isolates, respectively . Pseudomonas aeruginosa was inhibited by piperacillin/tazobactam in 89%, by cefepime in 87% and by ceftazidime in 85% . Imipenem, meropenem and cefpirome were less active (79%, 75% and 69% respectively) . All E . coli strains were inhibited by meropenem, 99% were inhibited by imipenem, cefepime and cefpirome . Ceftazidime was active against 95% and piperacillin/tazobactam against 92% of E . coli . All Klebsiella spp . were inhibited by meropenem, cefepime and cefpirome . Imipenem inhibited 99% and ceftazidime 98% of the Klebsiella isolates . Piperacillin/tazobactam was active against 95% of Klebsiella spp . In vitro carbapenems are still the most active of all antibiotics tested . The relatively high resistance of Pseudomonas spp . and Acinetobacter spp . to carbapenems reflects the wide use of carbapenems during the last years . However, most bacterial isolates are still sensitive to the tested broad spectrum beta-lactams.

Infect Control Hosp Epidemiol, 1999 Aug, 20(8), 565 - 7
The emergence of resistant strains of Acinetobacter baumannii: clinical and infection control implications; Dy ME et al.; A prospective study was undertaken to determine colonization rates, susceptibility profiles, and outcomes in patients with clinical isolates of Acinetobacter baumannii . Fifty percent of patients became colonized with A . baumannii, and 29% of these patients had clinical and colonizing isolates with discordant susceptibility profiles, without apparent relation to antibiotic use . Barrier infection control measures are necessary to prevent nosocomial transmission.

Kaohsiung J Med Sci, 1999 Jul, 15(7), 406 - 13
Acinetobacter baumannii bloodstream infection: clinical features and antimicrobial susceptibilities of isolates; Lai SW et al.; The number of nosocomial infections caused by Acinetobacter baumannii has increased in recent years . The purposes of this study are to discover the risk factors of transmission to prevent the nosocomial infection of A . baumannii . We retrospectively studied 36 patients with A . baumannii bacteremia at China Medical College Hospital from January 1996 to December 1997 . There were 23 males and 13 females . All bacteremia were acquired nosocomially . Malignancy (n = 8) and intracranial hemorrhage (n = 6) were the most common underlying diseases . Only one patient on arterial line disclosed intraarterial catheter-related A . baumannii bacteremia and 3 patients had evidence of A . baumannii pneumonia . Twenty-one patients (58%) had central venous catheters in place at the onset of bacteremia, but none was proven to be catheter-related infection . There were 32 patients (89%) with unknown portal of entry . Multivariate logistic regression analysis revealed that potential risk factors related to A . baumannii bacteremia were prior antimicrobial therapy (P < 0.05) . The most common clinical features of A . baumannii bacteremia were, in descending order, fever, leukocytosis, thrombocytopenia and hypotension . Eleven patients (30.6%) died directly from A . baumannii bacteremia . All isolates were resistant to ampicillin, cephalothin, cefonicid and moxalactam . The most alarming evidence was that 19% of isolates showed resistance to imipenem . Our findings emphasized that A . baumannii bacteremia had the following characteristics: usually acquired nosocomially, unknown portal of entry, and high multiresistance, especially the increasing resistance rate to imipenem . Imipenem must be reserved as a last-line agent to treat A . baumannii infections, so we want to suggest that the treatment of choice for A . baumannii is gentamicin, amikacin or ceftazidime.

J Chemother, 1999 Aug, 11(4), 260 - 5
Development of bacterial resistance to the third generation cephalosporins and their clinical use; Kolar M et al.; Development of Gram-negative rods resistance to the third generation cephalosporins (cefotaxime, ceftazidime, cefoperazone) in connection with their application at the University Hospital in Olomouc was evaluated in this study . The highest increase in resistance to cefotaxime was detected in Enterobacter cloacae (from 22.9% in 1995 to 49.0% in 1997) and Enterobacter agglomerans strains (28.0% - 40.5%) . In addition, increased resistance to ceftazidime in Acinetobacter baumannii (12.5% - 35.1%), Enterobacter aerogenes (7.4% - 20.9%), Enterobacter cloacae (16.7% - 47.2%) and Pseudomonas aeruginosa (4.0% - 26.3%) was observed . Finally, the greatest increase in frequency of strains resistant to cefoperazone was observed in E . aerogenes (18.4% - 30.1%), E . agglomerans (31.0% - 52.3%), E . cloacae (35.5% - 47.2%) and Providencia rettgeri (26.5% - 53.2%) . A 23.5% increase in third generation cephalosporin use was evident by evaluation of RDDD(ATB) parameters in 1996 and 1997 . Corresponding values for individual antibiotics were 26.5% cefotaxime, 20.7% ceftriaxone, and 40.3% ceftazidime increase . However, cefoperazone use decreased by 10.9%.

J Formos Med Assoc, 1999 Jul, 98(7), 465 - 73
Nosocomial gram-negative bacteremia in critically ill patients: epidemiologic characteristics and prognostic factors in 147 episodes; Jang TN et al.; Although gram-positive organisms are the most common causes of nosocomial bloodstream infections, gram-negative bacteremia carries higher risks of severe sepsis, septic shock, and death among critically ill patients in intensive care units (ICUs) . We performed a prospective epidemiologic analysis of nosocomial gram-negative bacteremia episodes among ICU patients and sought to identify risk factors for mortality among these patients . All episodes of nosocomial gram-negative bacteremia documented in five ICU wards of our hospital during a 2-year period were included . There were 147 episodes (124 patients) of gram-negative bacteremia documented during the study period . The overall mortality rate was 36.1%, and 77.4% of all deaths were directly related to the bloodstream infection . Gram-negative bacteremia was associated with prolonged ICU stay (45.7 d vs 6.1 d for all ICU patients) . The most common isolate was Acinetobacter baumannii, followed by Burkholderia cepacia and Enterobacter cloacae . The most frequent source of infection was the lower respiratory tract (32.0%) . Of the agents tested, ciprofloxacin, imipenem, and ceftazidime were the most active against the clinical isolates . Multivariate logistic regression analysis identified the presence of septic shock (odds ratio, OR = 17.66, p < 0.001) and rapidly fatal and ultimately fatal underlying conditions (OR = 3.47, p = 0.032) as being independent risk factors for mortality . Early appropriate antibiotic treatment did not result in significant improvement in survival . These findings suggest that prevention of lower respiratory tract colonization and nosocomial pneumonia are crucial for reducing the incidence of nosocomial gram-negative bacteremia in the ICU . Serious underlying illnesses and septic shock were the most important risk factors for death in these patients.

Int J Antimicrob Agents, 1999 Aug, 12(3), 199 - 202
Correlation between consumption of antimicrobials in humans and development of resistance in bacteria; Cristino JM; The correlation between consumption of antimicrobials in humans and the emergence of resistance in bacteria is complex and has proved difficult to establish . Besides antimicrobial use, many other distinct contributing factors are also involved in the issue . Despite this complexity, there is a substantial body of evidence that the use of antibiotics in prophylaxis and in therapy is associated with the development of resistance in the hospital and in the community . Some examples are reviewed, including increase of resistance in enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter spp., Streptococcus pneumoniae, Staphylococcus aureus, Coagulase Negative Staphylococci and Streptococcus pyogenes after the use of beta-lactam antibiotics, aminoglycosides, fluoroquinolones and macrolides . Success in reversing the rise of resistant strains has been rarely described . Two examples are highlighted, the reduction in the incidence of nasal carriage of penicillin-resistant pneumococci in Icelandic children, and a significant decline in erythromycin resistance in S . pyogenes after the reduction in the use of macrolides in Finland.

Chest, 1999 Aug, 116(2), 462 - 70
Role of different routes of tracheal colonization in the development of pneumonia in patients receiving mechanical ventilation; Cardenosa Cendrero JA et al.; STUDY OBJECTIVE: To evaluate the importance of the different pathogenic pathways involved in the development of ventilator-associated pneumonia (VAP) . DESIGN: Prospective study . SETTING: An 18-bed medical and surgical ICU . PATIENTS: One hundred twenty-three patients receiving mechanical ventilation (MV) . INTERVENTIONS: Tracheal, pharyngeal, and gastric samples were obtained simultaneously every 24 h . In cases where VAP was suspected clinically, bronchoscopy with protected specimen brush and BAL were performed . Semiquantitative cultures of pharyngeal samples and quantitative cultures for the remaining samples were obtained . RESULTS: Tracheal colonization at some time during MV was observed in 110 patients (89%) . Eighty patients had initial colonization, 34 patients had primary colonization, and 50 patients had secondary colonization . Nineteen patients had VAP, and 25 organisms were isolated . For none of these organisms was the stomach the initial site of colonization . Gram-positive organisms colonized mainly in the trachea during the first 24 h of MV (p<0.001) . On the contrary, enteric Gram-negative bacilli (p<0.001) and yeasts (p<0.002) colonized the trachea secondarily . Previous endotracheal intubation (p<0.005) and acute renal failure before admission to the ICU (p<0.001) were associated with colonization by Pseudomonas aeruginosa; prior antibiotics were associated with colonization by Acinetobacter baumanii (p<0.05) and yeasts (p<0.006); and cranial trauma was associated with Staphylococcus aureus colonization (p<0.035) . CONCLUSIONS: Although the stomach can be a source of organisms that colonize the tracheobronchial tree, it is a much less common source of the bacteria that cause VAP . The pattern of colonization and risk factors may be different according to the type of organisms involved.

Clin Infect Dis, 1999 May, 28(5), 1062 - 6
Reduction in the incidence of methicillin-resistant Staphylococcus aureus and ceftazidime-resistant Klebsiella pneumoniae following changes in a hospital antibiotic formulary; Landman D et al.; In 1995, changes in our hospital formulary were made to limit an outbreak of vancomycin-resistant enterococci and resulted in decreased usage of cephalosporins, imipenem, clindamycin, and vancomycin and increased usage of beta-lactam/beta-lactamase-inhibitor antibiotics . In this report, the effect of this formulary change on other resistant pathogens is described . Following the formulary change, there was a reduction in the monthly number (mean +/- SD) of patients with methicillin-resistant Staphylococcus aureus (from 21.9 +/- 8.1 to 17.2 +/- 7.2 patients/1,000 discharges; P = .03) and ceftazidime-resistant Klebsiella pneumoniae (from 8.6 +/- 4.3 to 5.7 +/- 4.0 patients/1,000 discharges; P = .02) . However, there was an increase in the number of patients with cultures positive for cefotaxime-resistant Acinetobacter species (from 2.4 +/- 2.2 to 5.4 +/- 4.0 patients/1,000 discharges; P = .02) . Altering an antibiotic formulary may be a possible mechanism to contain the spread of selected resistant pathogens . However, close surveillance is needed to detect the emergence of other resistant pathogens.

Clin Infect Dis, 1999 May, 28(5), 1017 - 24
Impact of use of multiple antimicrobials on changes in susceptibility of gram-negative aerobes; Friedrich LV et al.; Evaluation of antimicrobial usage vs . susceptibility relationships typically involves single agents . However, susceptibility profiles may be affected by multiple drugs . From 1992 through 1996, we studied relationships between drug usage and the susceptibility (only susceptibility rates of > or = 70%) of Acinetobacter anitratus (baumannii), Enterobacter aerogenes, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Serratia marcescens to 22 agents . Linear regression was used to assess usage of each agent vs . susceptibility to it and to all agents . Only relationships with a coefficient of determination of > or = 0.5 and a negative slope were evaluated and classified as increasing drug use and decreasing susceptibility (increasing D, decreasing %S) or decreasing drug use and increasing susceptibility (decreasing D, increasing %S) . The mean numbers (range) of drugs associated with a change in susceptibility were 1.7 (0-14) and 0.6 (0-7), respectively, for increasing D, decreasing %S and decreasing D, increasing %S relationships . Multiple antimicrobials are associated with susceptibility to other drugs; thus, surveillance of these relationships should not be limited to single drugs.

Clin Infect Dis, 1999 May, 28(5), 1008 - 11
Intravenous colistin as therapy for nosocomial infections caused by multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii; Levin AS et al.; Sixty nosocomial infections caused by Pseudomonas aeruginosa and Acinetobacter baumannii resistant to aminoglycosides, cephalosporins, quinolones, penicillins, monobactams, and imipenem were treated with colistin (one patient had two infections that are included as two different cases) . The infections were pneumonia (33% of patients), urinary tract infection (20%), primary bloodstream infection (15%), central nervous system infection (8%), peritonitis (7%), catheter-related infection (7%), and otitis media (2%) . A good outcome occurred for 35 patients (58%), and three patients died within the first 48 hours of treatment . The poorest results were observed in cases of pneumonia: only five (25%) of 20 had a good outcome . A good outcome occurred for four of five patients with central nervous system infections, although no intrathecal treatment was given . The main adverse effect of treatment was renal failure; 27% of patients with initially normal renal function had renal failure, and renal function worsened in 58% of patients with abnormal baseline creatinine levels . Colistin may be a good therapeutic option for the treatment of severe infections caused by multidrug-resistant P . aeruginosa and A . baumannii.

J Clin Microbiol, 1999 Sep, 37(9), 2962 - 7
Skin carriage of acinetobacters in Hong Kong; Chu YW et al.; We studied the carriage of Acinetobacter spp . at five superficial sites in 79 patients from two hospitals, in 133 healthy controls from the community (medical students and new nurses), and in 198 student nurses in different classes . A total of 431 isolates from 364 positive sites of 201 subjects and 124 blood culture isolates (1997 to 1998) were genospeciated by amplified ribosomal DNA restriction analysis . Genospecies 3 was the most common species . The carriage rate of student nurses (42 of 131) was significantly lower than that of new nurses from the community (25 of 38) (chi-square test, P = 0.0004; odds ratio {OR}, 4.08; 95% confidence limits, 1.78 to 9.41) but not significantly different (P = 0.1) from that of patients in the same hospital (20 of 42) . Genospecies from blood cultures and subjects (acute patients and student nurses) from Prince of Wales Hospital were similar to one another but different from subjects from the community or from another hospital (chi-square test, P < 0.0001) . Half of the subjects who were positive at at least two sites had different genospecies . Of the 28 sites examined, 68% showed strain variation among isolates of the same genospecies by random amplified polymorphic DNA analysis . Half of the 106 subjects who had samples taken again within 6 weeks or 6 months later were positive only once . In the 17 subjects who were positive on at least two occasions, each occasion yielded different genospecies in 13 subjects . Our results indicate that skin carriage in the majority of healthy subjects is characterized by low density, variation in genospecies and strains, short-term duration, and the typicality of a given locality.

Scand J Infect Dis, 1999, 31(2), 145 - 50
Distribution of Acinetobacter baumannii in a neurointensive care unit; Koljalg S et al.; In a 1-month prospective case-matched study we found Acinetobacter baumannii was a prevailing microbe simultaneously colonizing respiratory tract and skin of neurointensive care unit patients who stayed in our neurointensive care unit for more than 3 d . A . baumannii was not isolated from healthy case-matched controls . Based on their phenotypic properties and the results of amplified ribosomal DNA restriction analysis the 12 strains of Acinetobacter spp . isolated were identified as belonging to DNA group 2 (A . baumannii) . For epidemiological typing, Biolog system results of 95-carbon source oxidation, antibiograms and restriction endonuclease analysis were used . One predominant A . baumannii strain was found in all colonized patients, skin and respiratory tract were found mainly to be colonized with the same strain . The starting point of A . baumannii colonization seemed to vary with the individual patient . Environmental strains were different from patients' strains: they were metabolically more active, more resistant and had a different restriction endonuclease analysis profile.

Acta Paediatr, 1999 Jul, 88(7), 772 - 5
Acinetobacter junii causes life-threatening sepsis in preterm infants; de Beaufort AJ et al.; Acinetobacter junii caused sepsis in six preterm infants in our neonatal unit within 48 h . Each infant with clinical signs of systemic infection and activation of the acute phase response had two positive blood cultures with Acinetobacter junii . The sudden onset, the short duration of the outbreak and the fact that none of the infants were colonized by A . junii suggested a common source of A . junii administered directly into the blood . The only feature shared by all six affected newborns was an intravenous fat emulsion (Intralipid 10%), which was shown to be an excellent growth medium for A . junii . Sepsis did not occur in four infants with 20% fat emulsion or amino acids only . Vaminolact did not support growth of the outbreak strain . The immediate source of the outbreak could not be identified: samples of the actual feeds given were not available for investigation, but A . junii was not isolated from parenteral solutions with identical batch numbers used in the septic infants . We conclude that Acinetobacter junii can cause a life-threatening infection in preterm neonates . Contaminated intravenous fat emulsion is implicated as a possible source of the infection . As a part of rigid infection control, intravenous feedings should be prepared under aseptic conditions.

J Hosp Infect, 1999 Jul, 42(3), 201 - 4
Isolation of Acinetobacter spp . including A . baumannii from vegetables: implications for hospital-acquired infections; Berlau J et al.; A . baumannii is rarely recovered from the skin of patients or healthy European subjects as other genospecies predominate, but it isa significant nosocomial pathogen . The natural reservoir of this organism is therefore uncertain . We determined the isolation rates of Acinetobacter spp . from vegetables (as an indicator of the natural environment) using a selective technique and classified the genospecies by amplified ribosomal DNA restriction analysis (ARDRA) . Of the 177 samples of vegetables examined, 30 yielded Acinetobacter, with genospecies 2 and 11 being the most common, each with a frequency of 27% . MIC assays showed that strains of genospecies 1, 2, 3, and 13TU (the A . calcoaceticus-A . baumannii complex) were significantly more resistant than other genospecies to ciprofloxacin and gentamicin . Vegetables may therefore be a natural habitat of A . baumannii and provide a route by which these bacteria are introduced into hospitals with obvious implications for infection control.

Enferm Infecc Microbiol Clin, 1999 Jun-Jul, 17(6), 269 - 73
{Non fermentative gram negative bacilli isolated in a hospital laboratory}; Ronconi M et al.; OBJECTIVE: To report a prospective study on non fermentative gramnegative bacilli, excluded Pseudomonas aeruginosa, isolated at Dr . Julio C . Perrando Hospital in Resistencia (Argentina) . The goal of this study was to know their frequency and antimicrobial susceptibility . MATERIAL AND METHODS: For bacterial identifications we used biochemical tests . RESULTS: The greatest percentages of non fermentative gramnegative bacilli isolates were found in blood samples (25%), respiratory secretions and urine (23.9%) . Acinetobacter baumannii (34.7%), Pseudomonas fluorescens/Pseudomonas putida (15.2%), Stenotrophomonas maltophilia (9.7%) and Burkholderia cepacia (8.7%) were the non fermentative gramnegative bacilli species most commonly isolated . Distribution of microorganism strains according to samples and area is also assessed . Antimicrobial sensitivity of most commonly isolated non fermentative gramnegative bacilli strain analyzed . CONCLUSIONS: We concluded that non fermentative gramnegative bacilli are most frequently present in hospitalized that in outpatients and antibacterial therapy must be provided according to bacteriological information.

Microbiology, 1999 Jul, 145 ( Pt 7), 1711 - 20
The effect of heavy metals and other environmental conditions on the anaerobic phosphate metabolism of Acinetobacter johnsonii; Boswell CD et al.; A strain of Acinetobacter with potential for bioremediation of heavy metal-contaminated waters was isolated from a wastewater-treatment plant operating an enhanced biological phosphate removal process . NMR and extractive methods showed that polyphosphate accumulated aerobically was degraded under anaerobic conditions both in the presence and absence of cadmium or uranium (0.2-0.5 mM) . NMR showed that free phosphate was formed at the expense of polyphosphate, and an extractive technique indicated that this reaction could be stimulated by the presence of UO(2)2+ under these conditions . Energy-dispersive X-ray microanalysis demonstrated that only cadmium could enter the cells, and co-localized with intra-cellular granules containing phosphate and other divalent metals . The effects of other environmental parameters on the anaerobic phosphate metabolism were also investigated . Between pH 5.5 and 8.0, phosphate release increased with increasing pH . Between 4 degrees C and 37 degrees C, phosphate release increased with increasing temperature . The presence of nitrate at concentrations of 10 mM and above inhibited anoxic phosphate release, but supplying tungstate in the growth medium prior to anoxic incubation reduced the production of active nitrate reductase and alleviated this effect.

Rev Assoc Med Bras, 1999 Jan-Mar, 45(1), 2 - 8
{Treatment of pneumonia in hospitalized patients--results of a multicenter study using a fourth-generation cephalosporin (cefepime)}; de Medeiros EA; OBJECTIVE: To evaluate efficacy and safety of cefepime in severe pneumonia of hospitalized patients . DESIGN AND PATIENTS: A prospective, multicenter, open trial was performed with 148 patients (62 patients with nosocomial pneumonia; 34 with community-acquired pneumonia and 52 undefined forms) . Cefepime was intravenously administered (1,000 to 2,000 mg every 12 hours), and doses were adjusted for renal function . The efficacy endpoint was clinical response at 48 hours after completion of therapy . RESULTS: The mean age was 56.4 +/- 20.31 years . The most common bacterias isolated from patients with nosocomial pneumonia were: 5 (8.06%) Pseudomonas aeruginosa; 7 (11.29%) Pseudomonas sp.; 6 (9.68%) Klebsiella sp.; 3 (4.84%) E . coli; 2 (3.23%) Acinetobacter baumannii; 3 (4.84%) Staphylococcus aureus; 3 (4.84%) Streptococcus pneumoniae; 5 (8.06%) others . The most common isolates from patients with community-acquired pneumonia were: 2 (5.88%) Streptococcus pneumoniae; 1 (2.94%) S . aureus; 2 (5.88%) P . aeruginosa and 2 (5.88%) K . pneumoniae . Clinical efficacy was demonstrated in 137/148 (92.56%) of the cases since improvement was obtained in 20.27% and healing in 72.29% . Failure of the treatment was observed in 10 patients (6.75%) and one patient the evaluation was not possible . Adverse events were reported for 5/148 patients (3.38%) . CONCLUSION: Our data suggest that cefepime was safe and effective for treatment of severe pneumonia in hospitalized patients.

Am J Infect Control, 1999 Aug, 27(4), 327 - 31
Effectiveness of hand-cleansing agents for removing Acinetobacter baumannii strain from contaminated hands; Cardoso CL et al.; BACKGROUND: The effectiveness of hand-cleansing agents (plain liquid soap, 70% ethyl alcohol, 10% povidone-iodine, and 4% chlorhexidine gluconate) for removing a hospital strain of Acinetobacter baumannii from artificially contaminated hands of 5 volunteers was studied . METHODS: The experiments were performed by using a Latin square statistical design, with two 5 x 4 randomized blocks, and the results were estimated by ANOVA . In the first and second blocks, the fingertips of the volunteers were contaminated with approximately 10(3) colony-forming units (light contamination hand) and 10(6) colony-forming units (heavy contamination hand), respectively . RESULTS: In the first block, all products tested were effective, almost completely removing the microbial population of A baumannii artificially applied to the hands . In the second block, the use of hand-cleansing agents resulted in 91.36% (4% chlorhexidine), 92.33% (liquid soap), 98.49% (10% povidone-iodine), and 98.93% (70% ethyl alcohol) reduction in counts of A baumannii cells applied to the fingertips . The ethyl alcohol and povidone-iodine had significantly higher removal rates than plain soap and chlorhexidine (P <.05) . CONCLUSIONS: These results suggest that 70% ethyl alcohol and 10% povidone-iodine may be the most effective hand-cleansing agents for removing A baumannii strain from heavily contaminated hands (10(6) colony-forming units/fingertip).

Am J Respir Crit Care Med, 1999 Aug, 160(2), 608 - 13
Variations in etiology of ventilator-associated pneumonia across four treatment sites: implications for antimicrobial prescribing practices; Rello J et al.; This retrospective multicenter study compared microorganisms documented by quantitative cultures from bronchoscopic samples in episodes of ventilator-associated pneumonia (VAP) from three different institutions in Barcelona (B), Montevideo (M), and Seville (S) . The observations were compared with the findings reported by Trouillet and coworkers (AJRCCM 1998;157:531-539) in Paris (P) . The objective was to evaluate whether a classification of etiologies of VAP in four groups, based on the number of ventilation days and previous antimicrobial use, might contribute to establishing generalized guidelines for empirical therapy . Significant variations in etiologies (p < 0.05) were found in all of the microorganisms isolated from VAP episodes across three treatment sites when compared with the reference site (P) . In Group 1 (< 7 d and absence of antibiotics), Pseudomonas aeruginosa remained extremely infrequent (3 of 89, 3.3%) in the joint category, whereas the incidence of Acinetobacter baumannii was significantly higher, owing to M findings . On the other hand, one site (B) had a significantly lower incidence of multiresistant pathogens (Methicillin-resistant Staphylococcus aureus {MRSA} and nonfermenters other than P . aeruginosa), even in Group 2 (< 7 d and antibiotics), Group 3 (>/= 7 d and absence of antibiotics), and Group 4 (antibiotics and >/= 7 days) . Similar findings were documented when episodes were grouped according to Groups 1 and 3 of the ATS guidelines . We conclude that causes of VAP varied markedly across four treatment sites, resulting in the need for large-scale variations in antimicrobial prescribing practices . Instead of following general recommendations, antimicrobial prescribing practices for VAP should be based on up-to-date information of the pattern of multiresistant isolates from each institution.

J Chromatogr A, 1999 Jul 2, 848(1-2), 61 - 70
Selective adsorption of poly-His tagged glutaryl acylase on tailor-made metal chelate supports; Armisen P et al.; A poly-His tag was fused in the glutaryl acylase (GA) from Acinetobacter sp . strain YS114 cloned in E . coli yielding a fully active enzyme . Biochemical analyses showed that the tag did not alter the maturation of the chimeric GA (poly-His GA) that undergoes a complex post-translational processing from an inactive monomeric precursor to the active heterodimeric enzyme . This enzyme has been used as a model to develop a novel and very simple procedure for one-step purification of poly-His proteins via immobilized metal-ion affinity chromatography on tailor-made supports . It was intended to improve the selectivity of adsorption of the target protein on tailor-made chelate supports instead of performing a selective desorption . The rate and extent of the adsorption of proteins from a crude extract from E . coli and of pure poly-His tagged GA on different metal chelate supports was studied . Up to 90% of proteins from E . coli were adsorbed on commercial chelate supports having a high density of ligands attached to the support through long spacer arms, while this adsorption becomes almost negligible when using low ligand densities, short spacer arms and Zn2+ or Co2+ as cations . On the contrary, poly-His GA adsorbs strongly enough on all supports . A strong affinity interaction between the poly-His tail and a single chelate moiety seems to be the responsible for the adsorption of poly-His GA . By contrast, multipoint weak interactions involving a number of chelate moieties seem to be mainly responsible for adsorption of natural proteins . By using tailor-made affinity supports, a very simple procedure for one-step purification of GA with minimal adsorption of host proteins could be performed . Up to 20 mg of GA were adsorbed on each ml of chelate support while most of accompanying proteins were hardly adsorbed on such supports . Following few washing steps, the target enzyme was finally recovered (80% yield) by elution with 50 mM imidazole with a very high increment of specific activity (up to a 120 purification factor).

Acta Paediatr, 1999 May, 88(5), 576 - 8
Nosocomial meningitis in children after ventriculoperitoneal shunt insertion; Filka J et al.; This study reviews 33 cases of ventriculoperitoneal shunt (VPS) meningitis among 415 children after 540 shunt insertions within 8 y, in 9 paediatric intensive care units from 5 centres in Slovakia . The incidence of VPS meningitis was 6.3% per insertion . The most common organisms isolated from cerebrospinal fluid (CSF) and shunt were coagulase-negative staphylococci (52.8%), followed by Staphylococcus aureus (13.1%) and Pseudomonas aeruginosa (7.5%) . Seven of 15 assessed risk factors were significantly associated with VPS meningitis, compared with non-VPS meningitis: prior meningitis with hydrocephalus (15.1 vs 1.5%, p < 0.015), perinatal pathology (51.1 vs 1.5%, p < 0.001), very low birthweight (66.6 vs 16.2%, p < 0.001), polymicrobial nosocomial meningitis (30.3 vs 5.9%, p < 0.002), S . aureus (21.2 vs 7.3%, p < 0.05), coagulase-negative staphylococci (84.8 vs 30.9%, p < 0.001) and P . aeruginosa and Acinetobacter calcoaceticus (30.3 vs 4.5%, p < 0.001) in aetiology.

Res Microbiol, 1999 Jun, 150(5), 317 - 22
PCR detection of aminoglycoside resistance genes: a rapid molecular typing method for Acinetobacter baumannii; Noppe-Leclercq I et al.; Aminoglycoside resistance is common among strains of Acinetobacter baumannii responsible for nosocomial infections, and inactivation of these antibiotics by enzymatic modification is the main mechanism . Different types of aminoglycoside acetyltransferases (AAC), nucleotidyltransferases (ANT), and phosphotransferases (APH) are synthesized by clinical isolates, and several enzymes can be produced by a single strain . Using a multiplex PCR procedure carried out on bacterial thermolysates, we analyzed the aminoglycoside resistance gene content of strains belonging to eight clusters identified by pulsed-field gel electrophoresis . In a single reaction were combined three primer pairs in order to amplify the genes coding for AAC(6')-Ih, AAC(3)-I, and AAC(3)-II, three primer pairs for the genes coding for ANT(2'')-I, APH(3')-VI, and rRNA 16S as internal control, and finally two primer pairs for the genes coding for AAC(6')-Ib and APH(3')-I . According to the aminoglycoside resistance gene patterns, the strains of the eight clusters were distributed into seven classes . This simple and rapid (< 8 h) fingerprinting technique could be a useful tool for the epidemiological investigation of A . baumannii nosocomial infections.

Eur J Clin Microbiol Infect Dis, 1999 May, 18(5), 358 - 61
Six-year prospective study of risk and prognostic factors in patients with nosocomial sepsis caused by Acinetobacter baumannii; Gomez J et al.; In this prospective study, the risk factors associated with nosocomial sepsis Caused by Acinetobacter baumannii or Pseudomonas aeruginosa were compared . Prior use of broad-spectrum antibiotics, urinary tract catheter, prior surgery, and mechanical ventilation were significantly associated with nosocomial sepsis caused by Acinetobacter baumannii . The mean prognostic factors significantly associated with mortality were known focus of infection, multiresistant Acinetobacter baumannii, and inappropriate antibiotic treatment . Adequate knowledge of these findings is important to ensure appropriate management of patients and rational use of antibiotics.

J Bacteriol, 1999 Aug, 181(15), 4568 - 75
areABC genes determine the catabolism of aryl esters in Acinetobacter sp . Strain ADP1; Jones RM et al.; Acinetobacter sp . strain ADP1 is able to grow on a range of esters of aromatic alcohols, converting them to the corresponding aromatic carboxylic acids by the sequential action of three inducible enzymes: an areA-encoded esterase, an areB-encoded benzyl alcohol dehydrogenase, and an areC-encoded benzaldehyde dehydrogenase . The are genes, adjacent to each other on the chromosome and transcribed in the order areCBA, were located 3.5 kbp upstream of benK . benK, encoding a permease implicated in benzoate uptake, is at one end of the ben-cat supraoperonic cluster for benzoate catabolism by the beta-ketoadipate pathway . Two open reading frames which may encode a transcriptional regulator, areR, and a porin, benP, separate benK from areC . Each are gene was individually expressed to high specific activity in Escherichia coli . The relative activities against different substrates of the cloned enzymes were, within experimental error, identical to that of wild-type Acinetobacter sp . strain ADP1 grown on either benzyl acetate, benzyl alcohol, or 4-hydroxybenzyl alcohol as the carbon source . The substrate preferences of all three enzymes were broad, encompassing a range of substituted aromatic compounds and in the case of the AreA esterase, different carboxylic acids . The areA, areB, and areC genes were individually disrupted on the chromosome by insertion of a kanamycin resistance cassette, and the rates at which the resultant strains utilized substrates of the aryl ester catabolic pathway were severely reduced as determined by growth competitions between the mutant and wild-type strains.

Plasmid, 1999 Jul, 42(1), 60 - 6
Characterization of the Acinetobacter plasmid, pRAY, and the identification of regulatory sequences upstream of an aadB gene cassette on this plasmid; Segal H et al.; Primer extension analyses carried out to identify the transcription start site of an aadB gene, which is part of a gene cassette recombined at a secondary site on an Acinetobacter plasmid, pRAY, suggest that transcription control signals in Acinetobacter are similar but not identical to their counterparts in Escherichia coli . pRAY was sequenced . An AT-rich region, containing eight copies of the consensus sequence, AAAAAATAT, previously shown to be present in the origins of replication of other Acinetobacter plasmids, was predicted to be the origin of pRAY . The translation product of one of the 10 open reading frames identified on pRAY shows homology to the mobilization protein, MbeA .

Medicina (B Aires), 1999, 59(2), 138 - 42
{Epidemiologic consistency of polymerase chain reaction (PCR) based methods for the study of Acinotobacter baumannii infections}; Quelle LS et al.; Acinetobacter baumannii is one of the most frequent causative agents of nosocomial infections outbreaks . Consequently, a rapid and specific typing method that can identify epidemic strains is important in preventing their dissemination . To evaluate PCR (polymerase chain reaction)-based methods as epidemiological markers, epidemiologic concordance (EC) and the discriminatory power (D) of two of those methods: 1) arbitrary primed-PCR (AP-PCR), and 2) repetitive extragenic palindrome sequence-based PCR (REP-PCR), were analyzed . The results were compared with that of ribotyping using EcoRI, BglII and ClaI as restriction enzymes . These methods were applied to 69 A . baumannii isolates that included: 15 epidemiological unrelated isolates, 31 recovered from two outbreaks, and 23 obtained from endemic infections . Considering the unrelated isolates, D of ribotyping, AP-PCR and REP-PCR were 0.915, 0.904 and 0.847, respectively . The three methods showed the same EC with respect to the two analyzed outbreaks (100% and 83%, respectively), and the epidemic strains were uniformi differentiated from the co-transferred ones . Ribotyping classified the 23 isolates recovered from endemic infections in 4 different strains, while AP-PCR and REP-PCR identified 3 of them . Although, the 3 methods identified the most frequent disseminated strain . The mayor advantages of REP-PCR versus AP-PCR were reproducibility, and easier optimization . These advantages, in addition to the similar EC of the 3 methods, confirm REP-PCR as an appropriate marker to be used when rapid information about epidemiological A . baumannii infection analysis is required.

Microbios, 1999, 97(388), 145 - 52
Pharmacodynamic parameters and hydrophobicity changes induced by meropenem in Acinetobacter baumannii; Hostacka A; The suppression of bacterial growth of four Acinetobacter baumannii strains after 60 min exposure to meropenem at supra-inhibitory concentrations (postantibiotic effect; PAE) or at supra-subinhibitory concentrations (postantibiotic-sub-MIC effect; PA SME) was studied . The duration of the PAE was dependent on antibiotic concentration and on the strain . Meropenem at 2x or 4x the minimum inhibitory concentration (MIC), with the exception of one strain treated with 4x MIC, did not provoke suppression of bacterial growth compared with untreated controls . The highest concentration of meropenem (8x MIC) induced PAE for the strains tested in the range of 0.6-6.9 h . The effect of supra-subinhibitory concentrations of meropenem (2x, 4x or 8x MIC + 0.2x MIC) on bacterial growth was more efficient compared with supra-inhibitory concentrations alone . Two out of the four strains treated did not renew their growth . Bacterial suspensions exposed to meropenem showed reduced surface hydrophobicity . Decreases in hydrophobicity were associated with longer PAE and PA SME depending on the strain.

Eur J Biochem, 1999 Jul, 263(2), 587 - 95
Chemical and antigenic structure of the O-polysaccharide of the lipopolysaccharides from two Acinetobacter haemolyticus strains differing only in the anomeric configuration of one glycosyl residue in their O-antigens; Pantophlet R et al.; In a previous study {Pantophlet, R., Brade, L., Dijkshoorn, L., and Brade, H . (1998) J . Clin . Microbiol . 36, 1245-1250} the O-polysaccharide of the lipopolysaccharides (LPS) from Acinetobacter haemolyticus strains 57 and 61 exhibited indistinguishable banding-patterns following Western blot and immunostaining with homologous or heterologous rabbit antiserum . In this report, the molecular basis for the observed cross-reactivity was elucidated, by determining the chemical structure of the polysaccharides by compositional analysis and NMR spectroscopy . The structures are: {sequence: see text} for strain 61 {GulpNAcA, 2-acetamido-2-deoxy-gulopyranosyluronic acid; ManpNAcA, 2-acetamido-2-deoxy-mannopyranosyluronic acid; QuipN4N, 2,4-diamino-2,4,6-trideoxy-glucopyranose; acyl (S)-3-hydroxybutyryl}, thus, differing only in the anomeric configuration of the QuipN4N residue . The antigenic structures were determined by generating murine monoclonal antibodies, which were characterized by Western blot using LPS as antigen, by ELISA using LPS and de-O-acylated LPS as solid-phase antigens, and by ELISA inhibition studies using LPS, polysaccharide, and de-O-acylated LPS as inhibitors . Of the four antibodies selected, two were specific for the respective LPS moieties and two were cross-reactive . All antibodies were found to require the presence of the O-acetyl group for reactivity.

Perit Dial Int, 1999, 19 Suppl 2, S489 - 92
Pediatric peritoneal dialysis in Korea: practical solutions to the problems of peritoneal dialysis for children; Kim PK et al.; PURPOSE: To find and solve the common problems of peritoneal dialysis (PD) by analyzing the clinical data of pediatric PD performed in Korea . METHODS: We looked at 264 cases of continuous ambulatory peritoneal dialysis (CAPD) and acute PD that were performed in 18 institutions of pediatric nephrology in Korea from November 1987 to October 1997 . RESULTS: CAPD was performed in 114 cases.The mean age of the patients was 10.5+/-6.6 years, and the male-to-female ratio was 1.4:1 . The original causes of end-stage renal disease (ESRD) were proven in 92 cases (81%) . The most common renal diseases were focal segmental glomerulosclerosis (17%), reflux nephropathy (11%), and chronic glomerulonephritis (11%) . Mean duration of CAPD was 20 months+/-16.9 months . Peritonitis was the most common complication, and the peritonitis incidence was 0.96 episode per patient-year . Other complications were exit-site infection in 10 cases, obstruction in 7 cases, and leakage of dialysate in 6 cases . The most common etiologic organism of peritonitis was Staphylococcus aureus and the next most common was coagulase-negative staphylococcus . Acute PD was performed in 150 cases . The most common underlying causes were congenital heart disease, hemolytic uremic syndrome, sepsis, and dehydration . The mean duration was 10.3+/-11.3 days . The most common complication was peritonitis (78.3%) . The most common etiologic organisms of peritonitis were Staphylococcus aureus, coag-neg staphylococcus, Acinetobacter, and Pseudomonas . CONCLUSION: Reflux nephropathy should be emphasized in early diagnosis and treatment to prevent ESRD . Incidence of congenital anomaly (7%) as a original cause of ESRD was relatively low in Korea . Growth status was not significantly improved after CAPD . In acute PD, the incidence of peritonitis rapidly increased at 2 weeks after the start of dialysis.

Br Poult Sci, 1999 Mar, 40(1), 52 - 8
Water and air in two poultry processing plants' chilling facilities--a bacteriological survey; Fries R et al.; 1 . Water, aerosols and air in chilling facilities in 2 poultry abattoirs were bacteriologically examined . The different types of samples displayed a variety of bacterial loads and genera . 2 . The aerobic plate count in water from spray nozzles was about log10 2 to 3 in both plants . Flavobacterium, Alcaligenes, Acinetobacter and Pseudomonadaceae were predominant in these samples . 3 . The microbial load in air of the 2 plants was quite different, consisting mainly of Micrococcaceae and Gram-positive irregular rods . 4 . The aerobic plate count in aerosols was extremely high . The flora was the same as was found in the spray nozzles samples, plus Enterobacteriaceae, Micrococcaceae and streptococci, which presumably came from the air in the system . Cross-contamination may well occur in evaporative chilling.

J Antimicrob Chemother, 1999 Jun, 43 Suppl C, 51 - 4
Susceptibility to levofloxacin of clinical isolates of bacteria from intensive care and haematology/oncology patients in Switzerland: a multicentre study; Siegrist HH et al.; The objective of this study was to examine the susceptibility of clinical isolates to levofloxacin, a fluoroquinolone with extended activity against Gram-positive bacteria, and other antibiotics in 12 Swiss clinical microbiology laboratories using the NCCLS disc diffusion technique . Isolates were prospectively collected from intensive care units (ICUs (59%), oncology wards (7%) and other units with haematology/oncology patients (34%) from June 1995 to March 1996 . The levofloxacin breakpoints used were as recommended by the manufacturer . A total of 310 Gram-positive and 580 Gram-negative isolates from the respiratory tract (36%), skin/wounds (12%), blood (16%), urine (17%) and other sources (19%) were tested . The percentage of isolates susceptible to levofloxacin was 100% for Enterococcus spp . (38 strains), Streptococcus agalactiae (13), Streptococcus pneumoniae (65), Acinetobacter spp . (11), Citrobacter diversus (6), Citrobacter freundii (17), Klebsiella oxytoca (39), Morganella morganii (16), Proteus mirabilis (20), Proteus vulgaris (23), Serratia spp . (19), Stenotrophomonas maltophilia (10) and Haemophilus influenzae (41) . The percentage of isolates susceptible to levofloxacin for Staphylococcus aureus (95 strains, including 2% MRSA) was 94%, coagulase-negative staphylococci (85) 65%, Enterobacter spp . (75) 99%, Escherichia coli (111) 97%, Klebsiella pneumoniae (45) 98% and Pseudomonas aeruginosa (124) 87% . In conclusion, levofloxacin is a new fluoroquinolone to which the most common clinical isolates in Switzerland are susceptible . The susceptibility of Enterococcus spp . and S . pneumoniae to levofloxacin was particularly remarkable . This compound appears to be a promising therapeutic alternative for the treatment of Gram-positive infections.

J Antimicrob Chemother, 1999 Jun, 43 Suppl C, 43 - 50
In-vitro antibacterial activity of levofloxacin against hospital isolates: a multicentre study; Soussy CJ et al.; The objective of this study was to evaluate the activity of the fluoroquinolone, levofloxacin, against hospital isolates of bacteria . MICs of levofloxacin were determined for 2154 strains by agar dilution . Breakpoints for susceptibility testing were calculated using the agar diffusion technique with 5 micrograms discs . The activity of levofloxacin against nalidixic acid- and pefloxacin-susceptible Enterobacteriaceae (n = 668) was higher (MIC50/90 0.06-0.12 mg/L) than previously reported for ofloxacin . As seen with other fluoroquinolones, this activity was reduced against nalidixic acid-resistant and pefloxacin-intermediate and -resistant strains (MIC 1-8 mg/L) . MICs for Pseudomonas aeruginosa (n = 104) were between 0.12 and 128 mg/L . Levofloxacin had good activity against nalidixic acid- and pefloxacin-susceptible Acinetobacter baumannii (n = 12; MIC 0.06-0.25 mg/L), but the activity was reduced against nalidixic acid- and pefloxacin-resistant strains (n = 80; MIC 1-32 mg/L) . Haemophilus influenzae (n = 70), Haemophilus parainfluenzae (n = 47) and Moraxella catarrhalis (n = 64) were inhibited by low concentrations of levofloxacin (MICs 0.016-0.03 mg/L, 0.03-0.12 mg/L) and 0.03-0.12 mg/L, respectively) . Clostridium perfringens (n = 23; MIC 0.25-1 mg/L) was more susceptible than Bacteroides fragilis (n = 60; MIC 0.5-4 mg/L) . Levofloxacin showed superior activity compared with ofloxacin against methicillin-susceptible staphylococci (n = 107; MIC 0.03-0.5 mg/L); the resistant strains (MICs 2-32 mg/L) were usually also resistant to methicillin . Levofloxacin was less effective against enterococci (n = 105; MIC 1-32 mg/L), but streptococci (n = 192) and pneumococci (n = 129), including 58 penicillin-non-susceptible strains, were inhibited by low concentrations (MICs 0.5-2 mg/L) . According to the regression curve, zone diameters were usually 20-22 mm, 17-19 mm and 15-16 mm for MICs of 1, 2 and 4 mg/L, respectively . In conclusion, this study, performed on a large number of strains, confirms the superior anti-bacterial activity of levofloxacin compared with ofloxacin, especially against pathogens isolated from respiratory tract infections.

J Bacteriol, 1999 Jul, 181(14), 4292 - 8
The genes rubA and rubB for alkane degradation in Acinetobacter sp . strain ADP1 are in an operon with estB, encoding an esterase, and oxyR; Geissdorfer W et al.; Alkanes are oxidized in Acinetobacter sp . strain ADP1 by a three-component alkane monooxygenase, composed of alkane hydroxylase, rubredoxin, and rubredoxin reductase . rubA and rubB encode rubredoxin and a NAD(P)H-dependent rubredoxin reductase . We demonstrate here that single base pair substitutions in rubA or rubB lead to defects in alkane degradation, showing that both genes are essential for alkane utilization . Differences in the degradation capacity for hexadecane and dodecane in these mutants are discussed . Two genes, estB and oxyR, are located downstream of rubB, but are not necessary for alkane degradation . estB encodes a functional esterase . oxyR encodes a LysR-type transcriptional regulator, conferring resistance to hydrogen peroxide . rubA, rubB, estB, and oxyR constitute an operon, which is constitutively transcribed from a sigma70 promoter, and an estB-oxyR containing message is also transcribed from an internal promoter.

Appl Biochem Biotechnol, 1999 Spring, 77-79, 159 - 68
Site-directed mutagenesis study on the thermal stability of a chimeric PQQ glucose dehydrogenase and its structural interpretation; Witarto AB et al.; We have previously reported that a chimeric pyrroloquinoline quinone (PQQ) glucose dehydrogenase (GDH), E97A3, which was made up of 97% of Escherichia coli PQQGDH sequence and 3% of Acinetobacter calcoaceticus PQQGDH, showed increased thermal stability compared with both parental enzymes . Site-directed mutagenesis studies were carried out in order to investigate the role of amino-acid substitution at the C-terminal region, Ser771, of a chimeric PQQGDHs on their thermal stability . A series of Ser771 substitutions of a chimeric PQQGDH, E99A1, confirmed that hydrophobic interaction governs the thermal stability of the chimeric enzymes . Comparison of the thermal denaturation of E . coli PQQGDH and E97A3 followed by far-ultraviolet (UV) circular dichroism (CD) spectroscopy revealed that E97A3 acquired stability at the first step of denaturation, which is reversible, and where no significant secondary structure change was observed . These results suggested that the interaction between C-terminal and N-terminal regions may play a crucial role in maintaining the overall structure of beta-propeller proteins.

Mol Gen Genet, 1999 Jun, 261(4-5), 770 - 6
Specificity of the lipase-specific foldases of gram-negative bacteria and the role of the membrane anchor; El Khattabi M et al.; Folding of lipases that are secreted by Pseudomonads and other gram-negative bacteria via the type II secretion pathway is facilitated by dedicated chaperones, called lipase-specific foldases (Lifs) . Lifs are membrane-anchored proteins with a large periplasmic domain . The functional interaction between the Lif and its cognate lipase is specific, since the Pseudomonas aeruginosa Lif was found not to substitute for Lifs from Burkholderia glumae or Acinetobacter calcoaceticus . However, the P . aeruginosa Lif was able to activate the lipase from the closely related species P . alcaligenes . Hybrid proteins constructed from parts of the P . aeruginosa and B . glumae Lifs revealed that the C-terminal 138 amino acids of the B . glumae Lif determine the specificity of the interaction with the cognate lipase . Furthermore, the periplasmic domain of the B . glumae Lif was functional when cloned in frame with a cleavable signal sequence, which demonstrates that the membrane anchor is not essential for Lif function in vivo . However, the recombinant Lif was released into the medium, indicating that the function of the membrane anchor is to prevent secretion of the Lif together with the lipase.

Med Arh, 1999, 53(2), 81 - 3
{Trends in resistant bacteria isolated from a tube smear in intubated patients in intensive care}; Suljevic I et al.; Long standing antibiotics therapy has resulted in growing bacteria resistance . We took a tube smear and prepared culture with antibiogram from the fifty intubated patients in the Intensive care unit in the war period . Gram-negative germs were the dominant ones in total sum, and among them the Acinetobacter calcoaceticus (No 21), Pseudomonas aeruginosa (No 18), Klebsiella pneumoniae (No 18), were isolated most frequently . Pseudomonas aeruginosa showed high resistance to Gentamicin (64%), Amikacin (35%), Trimethoprim (66%), Pefloxacin (20%), Ofloxacin (25%), Ciprofloxacin (25%) . Klebsiella pneumoniae is resistant to Gentamicin (68%), Amikacin (22%), Cephalosporin (100%), Trimethoprim (31%), but it showed no resistance to chinolones . Acinetobacter calcoaceticus is resistant to Gentamicin (73%), Amikacin (36%), Cephalosporin (100%), Trimethoprim (63%), Pefloxacin (33%), Ofloxacin (67%), Ciprofloxacin (46%) . Staphylococcus aureus was the most frequent among Gram-positive germs and it was resistant to Penicillin (100%), Gentamicin (40%), Lincocin (18%), Trimethoprim (5%), Pefloxacin (13%), Methicillin (21%), Cephalosporin (8%) . The appearance of resistance on the antibiotics demands attentive follow-up aiming to influence the empirical application of antibiotics schemes depending on resistance.

Eur J Clin Microbiol Infect Dis, 1999 Apr, 18(4), 292 - 5
Evolution of resistance among clinical isolates of Acinetobacter over a 6-year period; Ruiz J et al.; The aim of this report was to study the evolution of susceptibilities of 1532 clinical isolates of Acinetobacter recovered over a period of 6 years . The minimal inhibitory concentrations (MICs) of 15 antimicrobial agents were determined for all the isolates . The respective percentages of resistant strains in the years 1991 and 1996 were as follows: ciprofloxacin, 54.4% and 90.4%; tobramycin, 33% and 71.8%; amikacin, 21% and 83.7%; ampicillin plus sulbactam, 65.7% and 84.1%; ceftazidime, 57.4% and 86.8%; ticarcillin, 70% and 89.4%; trimethoprim plus sulfamethoxazole, 41.1% and 88.9%; and imipenem, 1.3% and 80% . The MIC90s of ciprofloxacin, sparfloxacin, biapenem, meropenem, imipenem, cefepime, cefpirome, and rifampicin against 250 imipenem-resistant Acinetobacter strains were >32, >32, 128, >256, 256, >256, 256, and 16 mg/l, respectively . With serious infections, it was necessary to resort to the use of colistin, the only antibiotic active in vitro.

J Antimicrob Chemother, 1999 Jan, 43(1), 127 - 31
Biochemical characteristics of a carbapenemase from an Acinetobacter baumannii isolate collected in Buenos Aires, Argentina; Afzal-Shah M et al.; Three carbapenem-resistant Acinetobacter baumannii isolates were collected at a hospital in Buenos Aires, Argentina . Isoelectric focusing revealed multiple beta-lactamases, with two of the isolates showing identical profiles . A pI 6.9 carbapenemase with a molecular weight of 30 kDa was purified from one of these two isolates . The enzyme was predominantly a penicillinase, with its highest Vmax for oxacillin but highest Vmax/Km for benzylpenicillin . First-generation cephalosporins and imipenem were weaker substrates than penicillins, and oxyimino-aminothiazolyl cephalosporins were essentially stable . Meropenem-hydrolysing activity was not detected, despite resistance . The carbapenemase was inhibited by clavulanic acid and tazobactam, but not by EDTA . These kinetics place the enzyme into functional group 2; as an oxacillinase it could be placed in sub-group 2d or, as a zinc-independent carbapenemase, in sub-group 2f.

Can J Microbiol, 1999 Feb, 45(2), 116 - 24
Characterization of metal-resistant soil eubacteria by polymerase chain reaction--denaturing gradient gel electrophoresis with isolation of resistant strains; Macnaughton S et al.; Contamination of soils with heavy metal ions is a major problem on industrial and defense-related sites worldwide . The bioavailability and mobility of these contaminants is partially determined by the microbial biomass present at these sites . In this study, we have assessed the effect of the addition of a mixture of toxic metal salts on the prokaryotic community of microcosms consisting of sandy-loam soil using direct molecular analysis of the recoverable eubacterial 16S rDNA molecules by polymerase chain reaction--denaturing gradient gel electrophoresis (PCR-DGGE) and limited phospholipid fatty acid analysis (PLFA) . Addition of toxic metals (nonradioactive surrogates of Sr, Co, Cs, Cd) resulted in rapid (ca . 1 week) changes in the DGGE profile of the indigenous eubacterial community when compared with pristine controls . These changes were stable over the course of the experiment (8 weeks) . No changes in the eubacterial population of control microcosms were detected . The major changes in community structure in metal-contaminated microcosms consisted of the appearance of four novel bands not detected in controls . Sequence analysis of these bands suggested that two organisms related to the genus Acinetobacter and two related to the genus Burkholderia carried a selective advantage over other indigenous eubacteria under heavy metal induced stress . The Burkholderia spp . were then cultured and further characterized using lipid analysis.

Infection, 1999 May-Jun, 27(3), 208 - 11
Resistance to third-generation cephalosporins in adult gram-negative bacillary meningitis; Lu CH et al.; Ninety-three patients with gram-negative bacillary meningitis (GNBM) were identified at Kaohsiung Chang Gung Memorial Hospital, over a period of 12 years . Among them, eight showed resistance to third-generation cephalosporins, accounting for 9% of the total GNBM cases and 29% of the postneurosurgical GNBM cases . The resistant pathogens included Acinetobacter baumannii, Klebsiella pneumoniae, Citrobacter freundii and Morganella morganii . These eight patients, six males and two females aged 18-61 years, all had nosocomially acquired meningitis associated with head trauma and/or postneurosurgical states . Six patients received imipenem/cilastatin treatment; five survived and one died . The other two expired because they did not receive appropriate antibiotic treatment . Although third-generation cephalosporin-resistant GNBM is rare, its incidence has been increasing over the past 5 years . In patients with nosocomially-acquired postneurosurgical GNBM, the presence of third-generation cephalosporin resistance should therefore be highly suspected . The appropriate choice of antibiotic is essential for their survival.

EMBO J, 1999 Jun 15, 18(12), 3241 - 8
Protein tyrosine kinases in bacterial pathogens are associated with virulence and production of exopolysaccharide; Ilan O et al.; In eukaryotes, tyrosine protein phosphorylation has been studied extensively, while in bacteria, it is considered rare and is poorly defined . We demonstrate that Escherichia coli possesses a gene, etk, encoding an inner membrane protein that catalyses tyrosine autophosphorylation and phosphorylation of a synthetic co-polymer poly(Glu:Tyr) . This protein tyrosine kinase (PTK) was termed Ep85 or Etk . All the E.coli strains examined possessed etk; however, only a subset of pathogenic strains expressed it . Etk is homologous to several bacterial proteins including the Ptk protein of Acinetobacter johnsonii, which is the only other known prokaryotic PTK . Other Etk homologues are AmsA of the plant pathogen Erwinia amylovora and Orf6 of the human pathogen Klebsiella pneumoniae . These proteins are involved in the production of exopolysaccharide (EPS) required for virulence . We demonstrated that like Etk, AmsA and probably also Orf6 are PTKs . Taken together, these findings suggest that tyrosine protein phosphorylation in prokaryotes is more common than was appreciated previously, and that Etk and its homologues define a distinct protein family of prokaryotic membrane-associated PTKs involved in EPS production and virulence . These prokaryotic PTKs may serve as a new target for the development of new antibiotics.

J Mol Biol, 1999 Jun 4, 289(2), 319 - 33
The 1.7 A crystal structure of the apo form of the soluble quinoprotein glucose dehydrogenase from Acinetobacter calcoaceticus reveals a novel internal conserved sequence repeat; Oubrie A et al.; The crystal structure of a dimeric apo form of the soluble quinoprotein glucose dehydrogenase (s-GDH) from Acinetobacter calcoaceticus has been solved by multiple isomorphous replacement followed by density modification, and was subsequently refined at 1 . 72 A resolution to a final crystallographic R-factor of 16.5% and free R-factor of 20.8% {corrected} . The s-GDH monomer has a beta-propeller fold consisting of six four-stranded anti-parallel beta-sheets aligned around a pseudo 6-fold symmetry axis . The enzyme binds three calcium ions per monomer, two of which are located in the dimer interface . The third is bound in the putative active site, where it may bind and functionalize the pyrroloquinoline quinone (PQQ) cofactor . A data base search unexpectedly showed that four uncharacterized protein sequences are homologous to s-GDH with many residues in the putative active site absolutely conserved . This indicates that these homologs may have a similar structure and that they may catalyze similar PQQ-dependent reactions.A structure-based sequence alignment of the six four-stranded beta-sheets in s-GDH's beta-propeller fold shows an internally conserved sequence repeat that gives rise to two distinct conserved structural motifs . The first structural motif is found at the corner of the short beta-turn between the inner two beta-strands of the beta-sheets, where an Asp side-chain points back into the beta-sheet to form a hydrogen-bond with the OH/NH of a Tyr/Trp side-chain in the same beta-sheet . The second motif involves an Arg/Lys side-chain in the C beta-strand of one beta-sheet, which forms a bidentate salt-bridge with an Asp/Glu in the CD loop of the next beta-sheet . These intra and inter-beta-sheet hydrogen-bonds are likely to contribute to the stability of the s-GDH beta-propeller fold .

J Formos Med Assoc, 1999 Mar, 98(3), 214 - 7
Acinetobacter meningitis: four nosocomial cases; Chang WN et al.; We report the clinical features and therapeutic outcomes of four patients with multiantibiotic-resistant Acinetobacter meningitis . There were three males and one female, aged from 17 to 49 years . Three of them had suffered from head injuries with skull fractures, and the other suffered from an intracerebral hemorrhage and underwent a craniotomy . All four patients acquired nosocomial Acinetobacter meningitis, and multiantibiotic resistance developed . After treatment with imipenem/cilastatin, three of the four patients survived; one died of multiorgan failure . Because the clinical manifestations of Acinetobacter meningitis are similar to those of other gram-negative bacillary meningitis, the diagnosis can only be confirmed by bacterial culture . Resistance to multiple antibiotics, including third-generation cephalosporins, is frequently seen in patients with nosocomial Acinetobacter meningitis, and imipenem/cilastatin seems to be the antibiotic of choice for this potentially fatal central nervous system infection.

J Clin Microbiol, 1999 Jul, 37(7), 2170 - 5
Epidemiological study of an Acinetobacter baumannii outbreak by using a combination of antibiotyping and ribotyping; Biendo M et al.; From June to November 1994 (period 1) and from February to June 1995 (period 2), multiresistant Acinetobacter baumannii strains were isolated in intensive care units and surgical wards of the Amiens Teaching Hospital Center (Amiens, France) . Eighteen isolates were obtained from 17 (1%) of 1,706 patients admitted during both of these periods, giving an incidence rate of nosocomial infection per 1,000 patient days of 0.6% . Of 17 infected patients, 9 had pneumonia, 3 had urinary tract infection, 2 had peritonitis, 1 had septicemia, 1 had a catheter infection, and 1 had pneumonia and urinary tract infection . According to typing results, four antibiotic resistance profiles were detected: a, b, c, and d; seven ribotypes were distinguished by both restriction enzymes EcoRI and SalI (A, B, C, D, E, F, and G) . By combining antibiotyping and ribotyping, we obtained eight groups of strains (groups I to VIII) . Group I contained five strains (strains 4, 5, 7, 8, and 9) which had antibiogram pattern a and ribopattern A and constituted the outbreak strains . The strains of group II (strains 3, 10, 11, 13, and 14) were closely related to outbreak strain A and appeared to be variants of ribotype A (A2 {strain 3}; A4 {strain 10}; A5 {strains 11, 13, and 14}) . Groups III, IV, V, VI, VII, and VIII included strains which were epidemiologically unrelated to the strains of group I and were considered nonoutbreak strains.

J Hosp Infect, 1999 May, 42(1), 27 - 35
Survival of Acinetobacter baumannii on bed rails during an outbreak and during sporadic cases; Catalano M et al.; Genotypic methods showed Acinetobacter baumannii biotype 9 genotype I to be the epidemic strain on an outbreak in an intensive care unit (ICU) which lasted from January to April of 1996 . A cohort was established during March in which hospital personnel were assigned exclusively to A . baumannii infected or colonized patients . New patients were not admitted to the ICU until the last infected patient was discharged . However, strain I was isolated during April and vectors other than human carriage were suspected . The ICU comprised four sections; patients and beds were moved within them according the severity of diseases . Strain I was isolated from a bed rail nine days after the infected patient was discharged . This dry vector may explain the transmission of the epidemic strain between sections . The following July, four new infected patients were identified and three different strains, including the epidemic one, were recovered . The two other strains were also isolated from a bed rail . Although this environmental source does not explain by itself the transmission of an epidemic strain, it illustrates that dry vectors can be secondary reservoirs where A . baumannii can survive.

Crit Care Med, 1999 May, 27(5), 887 - 92
Nosocomial infections in medical intensive care units in the United States . National Nosocomial Infections Surveillance System; Richards MJ et al.; OBJECTIVE: To describe the epidemiology of nosocomial infections in medical intensive care units (ICUs) in the United States . DESIGN: Analysis of ICU surveillance data collected through the National Nosocomial Infections Surveillance (NNIS) System between 1992 and 1997 . SETTING: Medical ICUs in the United States . PATIENTS: A total of 181,993 patients . MEASUREMENTS AND MAIN RESULTS: Nosocomial infections were analyzed by infection site and pathogen distribution . Urinary tract infections were most frequent (31%), followed by pneumonia (27%) and primary bloodstream infections (19%) . Eighty-seven percent of primary bloodstream infections were associated with central lines, 86% of nosocomial pneumonia was associated with mechanical ventilation, and 95% of urinary tract infections were associated with urinary catheters . Coagulase-negative staphylococci (36%) were the most common bloodstream infection isolates, followed by enterococci (16%) and Staphylococcus aureus (13%) . Twelve percent of bloodstream isolates were fungi . The most frequent isolates from pneumonia were Gram-negative aerobic organisms (64%) . Pseudomonas aeruginosa (21%) was the most frequently isolated of these . S . aureus (20%) was isolated with similar frequency . Candida albicans was the most common single pathogen isolated from urine and made up just over half of the fungal isolates . Fungal urinary infections were associated with asymptomatic funguria rather than symptomatic urinary tract infections (p < .0001) . Certain pathogens were associated with device use: coagulase-negative staphylococci with central lines, P . aeruginosa and Acinetobacter species with ventilators, and fungal infections with urinary catheters . Patient nosocomial infection rates for the major sites correlated strongly with device use . Device exposure was controlled for by calculating device-associated infection rates for bloodstream infections, pneumonia, and urinary tract infections by dividing the number of device-associated infections by the number of days of device use . There was no association between these device-associated infection rates and number of hospital beds, number of ICU beds, or length of stay . There is a considerable variation within the distribution of each of these infection rates . CONCLUSIONS: The distribution of sites of infection in medical ICUs differed from that previously reported in NNIS ICU surveillance studies, largely as a result of anticipated low rates of surgical site infections . Primary bloodstream infections, pneumonia, and urinary tract infections associated with invasive devices made up the great majority of nosocomial infections . Coagulase-negative staphylococci were more frequently associated with primary bloodstream infections than reported from NNIS ICUs of all types in the 1980s, and enterococci were a more frequent isolate from bloodstream infections than S . aureus . Fungal urinary tract infections, often asymptomatic and associated with catheter use, were considerably more frequent than previously reported . Invasive device-associated infections were associated with specific pathogens . Although device-associated site-specific infection rates are currently our most useful rates for performing comparisons between ICUs, the considerable variation in these rates between ICUs indicates the need for further risk adjustment.

Int J Cardiol, 1999 Apr 30, 69(1), 97 - 9
Endocarditis due to Acinetobacter lwoffi on native mitral valve; Valero C et al.; Endocarditis due to Acinetobacter is a rare pathology with high mortality, reported mainly in hospitalized patients with predisposing risk factors . This is the second case of endocarditis due to Acinetobacter reported in our country in the last 10 years.

Am J Infect Control, 1999 Jun, 27(3), 247 - 53
Unusual genetic heterogeneity of Acinetobacter baumannii isolates in a university hospital in Italy; Villari P et al.; BACKGROUND: Acinetobacter baumannii has become an increasingly important nosocomial pathogen, particularly in intensive care units (ICUs) . The aim of this investigation was to study the molecular epidemiology of A baumanii in a university hospital in Italy . METHODS: All A baumanii isolates were collected and typed with phenotypic and genotypic methods during a 7-month period . A 1-year prospective surveillance of ICU-acquired infections was performed by using the National Nosocomial Infections Surveillance methodology . RESULTS: A baumanni accounted for 28.4% of all infections and 46.7% of all pneumonia acquired in the ICU, with a nosocomial infection rate of 12.4% or 8 infections per 1000 patient-days . Risk factors for A baumannii acquisition in the ICU were mechanical ventilation and previous use of broad-spectrum antibiotics, whereas administration of carbapenems showed a significant protective effect . Pulsed-field gel electrophoresis of genomic Apa I digests identified at least 5 outbreaks in the ICU caused by 5 different clones, one replacing the other in a well-defined temporal order . CONCLUSIONS: Whereas the sequential temporal cluster of epidemic clones in the ICU is intriguing and requires further research, the clear evidence of cross-contamination of A baumannii isolates involved with infections in the ICU demands extensive preventive efforts.

Eur J Clin Microbiol Infect Dis, 1999 Mar, 18(3), 179 - 83
Distribution of Acinetobacter species on skin of healthy humans; Berlau J et al.; The distribution of the 19 currently known genospecies of Acinetobacter on human skin, i.e . forehead, forearm and toe webs, was determined . Three selective media were compared for their specificity for all genospecies of Acinetobacter . A minimal-salts agar supplemented with 1% acetate proved to be more efficient than the Leeds medium for the isolation of most genospecies in mixed culture with other bacterial species . Acinetobacter isolates were provisionally identified using biochemical tests and the DNA transformation assay of Juni . Genospecies identification was performed using amplified ribosomal DNA restriction analysis, and duplicate isolates of the same genospecies from individuals were ruled out by random amplified polymorphic DNA analysis . Over 40% of 192 healthy volunteers carried Acinetobacter spp . at one or more body sites, and the frequencies of colonisation were as follows: forearm (51%), forehead (47%) and toe web (34%) . Genospecies 8/9 (Acinetobacter lwoffii) was the most common (61%), followed by genospecies 15BJ and 12 (Acinetobacter radioresistens) at 12.5% and 8%, respectively . The Acinetobacter baumannii-Acinetobacter calcoaceticus group (genospecies 1, 2, 3 and 13TU) that predominates in hospital-acquired infections was found in only one individual.

Diagn Microbiol Infect Dis, 1999 Jun, 34(2), 123 - 34
Evaluation of the in vitro activity of six broad-spectrum beta-lactam antimicrobial agents tested against over 2,000 clinical isolates from 22 medical centers in Japan . Japan Antimicrobial Resistance Study Group; Yamaguchi K et al.; Numerous broad-spectrum beta-lactam antimicrobial agents have been introduced into medical practice since 1985 . Although several of these compounds have advanced, infectious disease therapy resistances to them has also emerged world-wide . In 1997, a Japanese 22 medical center investigation was initiated to assess the continued utility of these agents (oxacillin or piperacillin, ceftazidime, cefepime, cefpirome, cefoperazone/sulbactam {C/S}, imipenem) . The participating medical centers represented a wide geographic distribution, and a common protocol and reagents were applied . Three control strains and a set of challenge organisms were provided to participant centers . Etest (AB BIODISK, Solna, Sweden) strips were used in concurrent tests of these organisms and a qualitative determination of participant skills in the identification of resistant and susceptible phenotypes was established . The quantitative controls demonstrated 97.7-99.2% of MIC values within established QC limits, and the qualitative (susceptibility category) controls documented a 97.3% agreement of participant results with that of reference values (1,320 total results) . Only 0.2% of values were false-susceptible errors . After the participant quality was assured, a total of 2,015 clinical strains were tested (10 strains from 10 different organism groups including methicillin-susceptible Staphylococcus aureus and coagulase-negative staphylococci {CoNS}, Escherichia coli, Klebsiella spp., Citrobacter freundii, Enterobacter spp., indole-positive Proteae, Serratia spp., Acinetobacter spp., and Pseudomonas aeruginosa) . The staphylococci were uniformly susceptible to all drugs tested except ceftazidime (MIC90, 24 micrograms/ml) that had a potency six- to 12-fold less than either cefepime or cefpirome . Only 3.7 and 45.1% of S . aureus and CoNS were susceptible to ceftazidime, respectively . Among E . coli and Klebsiella spp . the rank order of antimicrobial spectrum was imipenem = "fourth-generation" cephalosporins > ceftazidime > C/S > piperacillin . Possible extended spectrum beta-lactamase phenotypes were identified in 2.9-8.6% of these isolates . Isolates of C . freundii, Enterobacter spp., Proteae, and Serratia spp . that were resistant to ceftazidime and piperacillin remained susceptible to imipenem (0.0-4.5% resistance) and cefepime (0.0-5.0%) . Acinetobacters were inhibited best by C/S (99.5% susceptible) and least susceptible to piperacillin (MIC90, > 256 micrograms/ml; 21.7% susceptible) activity . P . aeruginosa isolates were most susceptible to cefepime (83.6%) and this zwitterionic cephalosporin also had the lowest level of resistance (9.1% of MICs at > or = 32 micrograms/ml) . Several multi-resistant organisms were identified in participant medical centers including S . marcescens strains resistant to cefepime, imipenem, or both observed in six hospitals . Clonal spread was documented in two medical centers; one hospital having two distinct epidemic clusters . Also a multi-resistant E . cloacae was found in two patients in the same hospital . Evaluations of carbapenem resistance in four species discovered only two strains (in same hospital) among 40 P . aeruginosa isolates (5.0%) with a metallo-enzyme, with nearly all of the remaining strains inhibited by an Ambler Class C enzyme inhibitor (BRL42715) indicating a hyperproduction of a chromosomal cephalosporinase . These results indicate that most newer beta-lactams remain widely useable in medical centers in Japan, but emerging often clonal, resistances have occurred . The overall rank order of antimicrobial spectrum against all ten tested bacterial groups favors the "fourth-generation" cephalosporin, cefepime (96.4% susceptible) as an equal to imipenem (95.9%) > C/S (90.9%) = cefpirome (90.0%) > ceftazidime (75.1%) = penicillins, either oxacillin or piperacillin (76.4%).

Epidemiol Mikrobiol Imunol, 1999 Apr, 48(2), 67 - 70
{Sensitivity to blood bactericidal activity and hydrophobicity of Acinetobacter baumannii after treatment with imipenem}; Hostacka A; Sensitivity to the serum bactericidal activity and surface hydrophobicity of Acinetobacter baumannii strains isolated from the urinary (UT) or respiratory tract (RT) of patients after exposure to imipenem at subinhibitory concentrations (sub-MICs) (1/4, 1/8 or 1/16 of their MICs) were tested . The antibiotic at the mentioned concentrations decreased significantly the sensitivity of strain UT to the bactericidal activity of human serum . Sensitivity to the bactericidal activity of serum of strain RT was affected only very ineffectively . Imipenem at 1/4 of their MICs reduced the cell surface hydrophobicity to 76.1% (strain UT) and to 81.9% (strain RT) compared with control values (without imipenem) . Lower concentrations of antibiotic influenced cell surface hydrophobicity only to a smaller extent . Possible decrease in sensitivity of bacteria to the bactericidal activity of serum after treatment with imipenem in "in vivo" experiments would manifest an increase in virulence of these strains.

J Bacteriol, 1999 Jun, 181(11), 3505 - 15
The physiological contribution of Acinetobacter PcaK, a transport system that acts upon protocatechuate, can be masked by the overlapping specificity of VanK; D'Argenio DA et al.; VanK is the fourth member of the ubiquitous major facilitator superfamily of transport proteins to be identified that, together with PcaK, BenK, and MucK, contributes to aromatic catabolism in Acinetobacter sp . strain ADP1 . VanK and PcaK have overlapping specificity for p-hydroxybenzoate and, most clearly, for protocatechuate: inactivation of both proteins severely impairs growth with protocatechuate, and the activity of either protein alone can mask the phenotype associated with inactivation of its homolog . Furthermore, vanK pcaK double-knockout mutants appear completely unable to grow in liquid culture with the hydroaromatic compound quinate, although such cells on plates convert quinate to protocatechuate, which then accumulates extracellularly and is readily visible as purple staining . This provides genetic evidence that quinate is converted to protocatechuate in the periplasm and is in line with the early argument that quinate catabolism should be physically separated from aromatic amino acid biosynthesis in the cytoplasm so as to avoid potential competition for intermediates common to both pathways . Previous studies of aromatic catabolism in Acinetobacter have taken advantage of the ability to select directly strains that contain a spontaneous mutation blocking the beta-ketoadipate pathway and preventing the toxic accumulation of carboxymuconate . By using this procedure, strains with a mutation in structural or regulatory genes blocking degradation of vanillate, p-hydroxybenzoate, or protocatechuate were selected . In this study, the overlapping specificity of the VanK and PcaK permeases was exploited to directly select strains with a mutation in either vanK or pcaK . Spontaneous mutations identified in vanK include a hot spot for frameshift mutation due to contraction of a G6 mononucleotide repeat as well as point mutations producing amino acid substitutions useful for analysis of VanK structure and function . Preliminary second-site suppression analysis using transformation-facilitated PCR mutagenesis in one VanK mutant gave results similar to those using LacY, the prototypic member of the major facilitator superfamily, consistent with the two proteins having a similar mechanism of action . The selection for transport mutants described here for Acinetobacter may also be applicable to Pseudomonas putida, where the PcaK permease has an additional role in chemotaxis.

J Bacteriol, 1999 Jun, 181(11), 3494 - 504
Genetic analysis of a chromosomal region containing vanA and vanB, genes required for conversion of either ferulate or vanillate to protocatechuate in Acinetobacter; Segura A et al.; VanA and VanB form an oxygenative demethylase that converts vanillate to protocatechuate in microorganisms . Ferulate, an abundant phytochemical, had been shown to be metabolized through a vanillate intermediate in several Pseudomonas isolates, and biochemical evidence had indicated that vanillate also is an intermediate in ferulate catabolism by Acinetobacter . Genetic evidence supporting this conclusion was obtained by characterization of mutant Acinetobacter strains blocked in catabolism of both ferulate and vanillate . Cloned Acinetobacter vanA and vanB were shown to be members of a chromosomal segment remote from a supraoperonic cluster containing other genes required for completion of the catabolism of ferulate and its structural analogs, caffeate and coumarate, through protocatechuate . The nucleotide sequence of DNA containing vanA and vanB demonstrated the presence of genes that, on the basis of nucleotide sequence similarity, appeared to be associated with transport of aromatic compounds, metabolism of such compounds, or iron scavenging . Spontaneous deletion of 100 kb of DNA containing this segment does not impede the growth of cells with simple carbon sources other than vanillate or ferulate . Additional spontaneous mutations blocking vanA and vanB expression were shown to be mediated by IS1236, including insertion of the newly discovered composite transposon Tn5613 . On the whole, vanA and vanB appear to be located within a nonessential genetic region that exhibits considerable genetic malleability in Acinetobacter . The overall organization of genes neighboring Acinetobacter vanA and vanB, including a putative transcriptional regulatory gene that is convergently transcribed and overlaps vanB, is conserved in Pseudomonas aeruginosa but has undergone radical rearrangement in other Pseudomonas species.

Antimicrob Agents Chemother, 1999 Jun, 43(6), 1406 - 11
In vivo efficacies of combinations of beta-lactams, beta-lactamase inhibitors, and rifampin against Acinetobacter baumannii in a mouse pneumonia model; Wolff M et al.; The effects of various regimens containing combinations of beta-lactams, beta-lactam inhibitor(s), and rifampin were assessed in a recently described mouse model of Acinetobacter baumannii pneumonia (M . L . Joly-Guillou, M . Wolff, J . J . Pocidalo, F . Walker, and C . Carbon, Antimicrob . Agents Chemother . 41:345-351, 1997) . Two aspects of the therapeutic response were studied: the kinetics of the bactericidal effect (treatment was initiated 3 h after intratracheal inoculation, and bacterial counts were determined over a 24-h period) and survival (treatment was initiated 8 h after inoculation, and the cumulative mortality rate was assessed on day 5) . Two clinical strains were used: a cephalosporinase-producing strain (SAN-94040) and a multiresistant strain (RCH-69) . For SAN-94040 and RCH-69, MICs and MBCs (milligrams per liter) were as follows: ticarcillin, 32, 64, 256, and >256, respectively; ticarcillin-clavulanate, 32, 64, and 512, and >512, respectively; imipenem, 0.5, 0.5, 8, and 32, respectively; sulbactam, 0.5, 0.5, 8, and 8, respectively; and rifampin, 8, 8, 4, and 4, respectively . Against SAN-94040, four regimens, i.e., imipenem, sulbactam, imipenem-rifampin, and ticarcillin-clavulanate (at a 25/1 ratio)-sulbactam produced a true bactericidal effect (>/=3-log10 reduction of CFU/g of lung) . The best survival rate (i.e., 93%) was obtained with the combination of ticarcillin-clavulanate-sulbactam, and regimens containing rifampin provided a survival rate of >/=65% . Against RCH-69, only regimens containing rifampin and the combination of imipenem-sulbactam had a true bactericidal effect . The best survival rates (>/=80%) were obtained with regimens containing rifampin and sulbactam . These results suggest that nonclassical combinations of beta-lactams, beta-lactamase inhibitors, and rifampin should be considered for the treatment of nosocomial pneumonia due to A . baumannii.

Appl Environ Microbiol, 1999 Jun, 65(6), 2697 - 702
Enhancement of solubilization and biodegradation of polyaromatic hydrocarbons by the bioemulsifier alasan; Barkay T et al.; Alasan, a high-molecular-weight bioemulsifier complex of an anionic polysaccharide and proteins that is produced by Acinetobacter radioresistens KA53 (S . Navon-Venezia, Z . Zosim, A . Gottlieb, R . Legmann, S . Carmeli, E . Z . Ron, and E . Rosenberg, Appl . Environ . Microbiol . 61:3240-3244, 1995), enhanced the aqueous solubility and biodegradation rates of polyaromatic hydrocarbons (PAHs) . In the presence of 500 microg of alasan ml-1, the apparent aqueous solubilities of phenanthrene, fluoranthene, and pyrene were increased 6.6-, 25.7-, and 19.8-fold, respectively . Physicochemical characterization of the solubilization activity suggested that alasan solubilizes PAHs by a physical interaction, most likely of a hydrophobic nature, and that this interaction is slowly reversible . Moreover, the increase in apparent aqueous solubility of PAHs does not depend on the conformation of alasan and is not affected by the formation of multimolecular aggregates of alasan above its saturation concentration . The presence of alasan more than doubled the rate of {14C}fluoranthene mineralization and significantly increased the rate of {14C}phenanthrene mineralization by Sphingomonas paucimobilis EPA505 . The results suggest that alasan-enhanced solubility of hydrophobic compounds has potential applications in bioremediation.

Appl Environ Microbiol, 1999 Jun, 65(6), 2622 - 30
Characterization of a Pseudomonas putida allylic alcohol dehydrogenase induced by growth on 2-methyl-3-buten-2-ol; Malone VF et al.; We have been working to develop an enzymatic assay for the alcohol 2-methyl-3-buten-2-ol (232-MB), which is produced and emitted by certain pines . To this end we have isolated the soil bacterium Pseudomonas putida MB-1, which uses 232-MB as a sole carbon source . Strain MB-1 contains inducible 3-methyl-2-buten-1-ol (321-MB) and 3-methyl-2-buten-1-al dehydrogenases, suggesting that 232-MB is metabolized by isomerization to 321-MB followed by oxidation . 321-MB dehydrogenase was purified to near-homogeneity and found to be a tetramer (151 kDa) with a subunit mass of 37,700 Da . It catalyzes NAD+-dependent, reversible oxidation of 321-MB to 3-methyl-2-buten-1-al . The optimum pH for the oxidation reaction was 10.0, while that for the reduction reaction was 5.4 . 321-MB dehydrogenase oxidized a wide variety of aliphatic and aromatic alcohols but exhibited the highest catalytic specificity with allylic or benzylic substrates, including 321-MB, 3-chloro-2-buten-1-ol, and 3-aminobenzyl alcohol . The N-terminal sequence of the enzyme contained a region of 64% identity with the TOL plasmid-encoded benzyl alcohol dehydrogenase of P . putida . The latter enzyme and the chromosomally encoded benzyl alcohol dehydrogenase of Acinetobacter calcoaceticus were also found to catalyze 321-MB oxidation . These findings suggest that 321-MB dehydrogenase and other bacterial benzyl alcohol dehydrogenases are broad-specificity allylic and benzylic alcohol dehydrogenases that, in conjunction with a 232-MB isomerase, might be useful in an enzyme-linked assay for 232-MB.

Electrophoresis, 1999 Apr-May, 20(4-5), 781 - 9
Induction of heat shock proteins in response to primary alcohols in Acinetobacter calcoaceticus; Benndorf D et al.; Cells of Acinetobacter calcoaceticus 69-V, a species able to metabolize a range of aliphatic hydrocarbons and alcohols, were confronted with ethanol, butanol, hexanol or heat shock during growth on acetate as sole source of carbon and energy . The primary alcohols and the heat shock led to the synthesis of new proteins or amplified expression of specific, common and general proteins, which were detected by silver staining after two-dimensional gel electrophoresis . Some of the alcohol-inducible proteins were identified as heat shock proteins by comparing protein patterns of alcohol-shocked cells with those of heat-shocked cells, and by N-terminal amino acid sequencing . DnaK was found to be amplified after all treatments, but GroEI only after heat shock and ethanol treatment . The N-terminal amino acid sequence of the protein, which was considerably amplified after alcohol treatment and heat shock, shows homology to HtpG (high temperature protein G) . Some of the heat shock proteins induced by ethanol differ from those induced by butanol and hexanol, suggesting there are at least two different signals for the induction of some heat shock proteins by primary alcohols . This could be due to the different localization of ethanol, butanol and hexanol in the membrane, or because higher cytoplasmic concentrations of ethanol than of butanol or hexanol were applied in these tests in order to keep concentrations of the alcohols in the membrane roughly similar . Besides heat shock proteins, a group of proteins were observed which were only induced by butanol and hexanol, possibly indicating the existence of a further defense mechanism against high concentrations of hydrophobic substrates preventing protein denaturation and membrane damage.

Infect Immun, 1999 Jun, 67(6), 2834 - 40
Effects of cytokines and endotoxin on the intracellular growth of bacteria; Kanangat S et al.; Patients with unresolving acute respiratory distress syndrome (ARDS) have persistently elevated levels of proinflammatory cytokines in the lungs and circulation and increased rates of bacterial infections . Phagocytic cells hyperactivated with lipopolysaccharide (LPS), which induces high levels of proinflammatory cytokines in monocytic cells, are inefficient in killing ingested bacteria despite having intact phagocytic activity . On the other hand, phagocytic cells that are activated with an analogue of LPS that does not induce the expression of proinflammatory cytokines effectively ingest and kill bacteria . We hypothesized that in the presence of high concentrations of proinflammatory cytokines, bacteria may adapt and utilize cytokines to their growth advantage . To test our hypothesis, we primed a human monocytic cell line (U937) with escalating concentrations of the proinflammatory cytokines tumor necrosis factor alpha, interleukin-1beta (IL-1beta), and IL-6 and with LPS . These cells were then exposed to fresh isolates of three common nosocomial pathogens: Staphylococcus aureus, Pseudomonas aeruginosa, and an Acinetobacter sp . In human monocytes primed with lower concentrations of proinflammatory cytokines (10 to 250 pg) or LPS (1 and 10 ng), intracellular bacterial growth decreased . However, when human monocytes were primed with higher concentrations of proinflammatory cytokines (1 to 10 ng) or LPS (1 to 10 micrograms), intracellular growth of the tested bacteria increased significantly (P <0.0001) . These results were reproduced with peripheral blood monocytes obtained from normal healthy volunteers . The specificity of the cytokine activity was demonstrated by neutralizing the cytokines with specific antibodies . Our findings provide a possible mechanism to explain the frequent development of bacterial infections in patients with an intense and protracted inflammatory response.

J Med Entomol, 1999 May, 36(3), 382 - 8
Rearing stable fly larvae (Diptera: Muscidae) on an egg yolk medium; Lysyk TJ et al.; The growth and survival of Stomoxys calcitrans (L.) larvae on egg yolk medium inoculated with bacteria isolated from a colony of stable flies was evaluated . Five species of bacteria--Acinetobacter sp., Aeromonas sp., Empedobacter breve (Holmes & Owen), Flavobacterium odoratum Stutzer, and Serratia marcescens Bizio--were identified according to fatty acid profiles using a microbial identification system . Larvae failed to develop on uninoculated plates, confirming that bacteria are required to complete development . Larvae also failed to complete development on plates inoculated with Aeromonas sp . and S . marcescens, and died during the 1st instar . Larvae completed development on the remaining 3 bacterial species as well as on Escherichia coli (Migula) . Survival was generally higher when larvae were reared on Acinetobacter sp . and F . odoratum compared with E . coli and E . breve . Egg density did not influence larval survival, although the variability in survival was lowest using 20 and 40 eggs per plate . Larval survival in mixed cultures of Acinetobacter and Flavobacterium averaged 22.7% lower than survival in the pure cultures, and averaged 21.6% higher in mixed cultures of Empedobacter and Flavobacterium compared with pure cultures . Larval survival in mixed cultures did not differ significantly from mean survival in pure cultures for combinations of Acinetobacter and E . coli, Acinetobacter and Empedobacter, E . coli and Empedobacter, and E . coli and Flavobacterium . Larval developmental time was faster on all mixed bacterial cultures compared with developmental time on pure bacterial cultures . Optimal sample sizes and egg numbers are presented for detecting specified differences in larval survival . This rearing procedure will be useful for studying insect-microbe interactions and evaluating mortality using bacterial agents.

Biochem Biophys Res Commun, 1999 May 27, 259(1), 220 - 3
Allylic or benzylic stabilization is essential for catalysis by bacterial benzyl alcohol dehydrogenases; Curtis AJ et al.; Benzyl alcohol dehydrogenase from Acinetobacter calcoaceticus (AC-BADH) and TOL plasmid-encoded benzyl alcohol dehydrogenase from Pseudomonas putida (TOL-BADH) have previously been shown to oxidize a variety of aromatic alcohols but not aliphatic substrates . Here, we have expressed the genes for AC-BADH and TOL-BADH in Escherichia coli, purified the resulting over-expressed enzymes, and shown that each is an effective catalyst of both benzylic and allylic alcohol oxidation, but not of oxidation of nonallylic analogs . Enzyme specificity (kcat/Km) for both enzymes was higher with an aliphatic, allylic alcohol (3-methyl-2-buten-1-ol) than with benzyl alcohol . These results suggest that bacterial benzyl alcohol dehydrogenases use the resonance stabilization provided by allylic and benzylic alcohols to promote catalysis .

J Med Microbiol, 1999 Mar, 48(3), 287 - 96
Genotypic and phenotypic similarity of multiresistant Acinetobacter baumannii isolates in the Czech Republic; Nemec A et al.; The diversity of 103 clinical isolates of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex obtained between 1991 and 1997 from 17 Czech hospitals was studied by ribotyping, biotyping, plasmid profiling and antibiotic susceptibility testing . According to the EcoRI ribotypes, all but one of these isolates were identified to the DNA group level: 77 isolates were allocated to DNA group 2 (A . baumannii), 14 to DNA group 3, 10 to DNA group 13 sensu Tjernberg and Ursing and one to DNA group 1 (A . calcoaceticus) . In total, 50 different EcoRI ribotypes and 10 biotypes were observed . Plasmids were found in 92% of the isolates and a high variability in plasmid profiles was found in isolates of the same DNA group . The combination of typing profiles allowed two predominant groups (termed A and B) to be distinguished among the A . baumannii isolates (37 and eight isolates, respectively) that shared a specific ribotype and were highly similar in other properties . These two groups comprised both sporadic and outbreak isolates and were found in most localities . Group A and B isolates were markedly more resistant to antibiotics than most of the remaining isolates, thus representing 85% of all multiresistant isolates . The features of groups A and B corresponded to those of two epidemic clones identified recently among hospital strains in north-western Europe.

Chest, 1999 May, 115(5), 1378 - 82
Risk factors for an outbreak of multi-drug-resistant Acinetobacter nosocomial pneumonia among intubated patients; Husni RN et al.; INTRODUCTION: Acinetobacter baumanii is a Gram-negative coccobacillus that is normally a commensal pathogen but can be a nosocomial pathogen . An epidemiologic study was performed to investigate an outbreak of A baumanii that occurred in our medical intensive care unit (MICU) from March to September 1995 . METHODS: A case-control study was performed by retrospective chart review, comparing case patients to randomly selected patients who were mechanically ventilated in the MICU for at least 1 week during the outbreak . A case patient was defined as any patient with an Acinetobacter infection in which the epidemic strain was considered to be a pathogen . The epidemic strain was defined by its antibiogram . Case patients and control patients were compared for age, gender, underlying disease, acute physiology and chronic health evaluation III score, length of MICU stay, prior antibiotic use, presence of fever, sepsis, type of pulmonary infiltrate, and outcome . Environmental and hand-washing studies also were performed during the period of the outbreak . Molecular typing was performed on available bloodstream isolates . RESULTS: There were 15 cases of A baumanii nosocomial pneumonia . Fifty percent were bacteremic; one chart was unavailable for review . Twenty-nine patients were identified as control patients . The mean age for case patients was 50 (range, 21 to 84) . The mean duration of time from admission to the ICU to infection was 12.8 days (range, 4 to 40) . Sepsis developed in 35% of the case patients . Forty-three percent of the case patients died during their hospitalization, with two of those deaths attributed to Acinetobacter infection . Univariate analysis showed that prior use of ceftazidime was associated with infection with Acinetobacter (11/14 case patients compared to 11/29 control patients; p < 0.01) . Pulsed-field gel electrophoresis revealed two strains to be responsible for the outbreak . Hand washing was performed before patient contact by only 10% of health-care workers, and only 32% washed their hands after patient contact . CONCLUSION: The use of ceftazidime was associated with an increased risk of nosocomial pneumonia with resistant strains of Acinetobacter . Health-care workers need to improve compliance with hand-washing recommendations.

J Clin Microbiol, 1999 Jun, 37(6), 1693 - 8
Use of a murine O-antigen-specific monoclonal antibody to identify Acinetobacter strains of unnamed genomic species 13 Sensu Tjernberg and Ursing; Pantophlet R et al.; A monoclonal antibody against the O-antigenic polysaccharide chain of the lipopolysaccharide (LPS) of Acinetobacter strains belonging to the unnamed genomic species 13 Sensu Tjernberg and Ursing (13TU) was obtained after immunization of BALB/c mice with heat-killed bacteria and was characterized by enzyme immunoassay and Western blot analysis, by use of LPS and proteinase K-treated bacterial lysates, analyses in which the antibody was shown to be highly specific for the homologous antigen . In addition, when tested in dot and Western blots, reactivity was observed with 9 of 18 Acinetobacter strains of genomic species 13TU which had been isolated in Germany and Denmark; no reactivity was observed with strains of other genomic species, including the closely related genomic groups 1 (A . calcoaceticus), 2 (A . baumannii), and 3 (unnamed), or with other gram-negative bacteria . The antibody described here represents a convenient reagent for the simple, economical, and accurate differentiation of clinical isolates of genomic species 13TU from other Acinetobacter strains . Although the antibody does not identify all isolates of this genomic group, it is evident that it will be a useful reagent in the development of a serotyping scheme for clinical laboratories.

Sci Total Environ, 1999 Mar 9, 227(2-3), 237 - 47
Comparison of the fuel oil biodegradation potential of hydrocarbon-assimilating microorganisms isolated from a temperate agricultural soil; Chaineau CH et al.; Strains of hydrocarbon-degrading microorganisms (bacteria and fungi) were isolated from an agricultural soil in France . In a field, a portion was treated with oily cuttings resulting from the drilling of an onshore well . The cuttings which were spread at the rate of 600 g HC m-2 contained 10% of fuel oil hydrocarbons (HC) . Another part of the field was left untreated . Three months after HC spreading, HC adapted bacteria and fungi were isolated at different soil depths in the two plots and identified . The biodegradation potential of the isolated strains was monitored by measuring the degradation rate of total HC, saturated hydrocarbons, aromatic hydrocarbons and resins of the fuel . Bacteria of the genera Pseudomonas, Brevundimonas Sphingomonas, Acinetobacter, Rhodococcus, Arthrobacter, Corynebacterium and fungi belonging to Aspergillus, Penicillium, Beauveria, Acremonium, Cladosporium, Fusarium, and Trichoderma were identified . The most active strains in the assimilation of saturates and aromatics were Arthrobacter sp., Sphingomonas spiritivorum, Acinetobacter baumanii, Beauveria alba and Penicillum simplicissimum . The biodegradation potential of the hydrocarbon utilizing microorganisms isolated from polluted or unpolluted soils were similar . In laboratory pure cultures, saturated HC were more degraded than aromatic HC, whereas resins were resistant to microbial attack . On an average, individual bacterial strains were more active than fungi in HC biodegradation.

J Med Microbiol, 1999 May, 48(5), 479 - 83
Some immunological properties of lipopolysaccharide from Acinetobacter baumannii; Garcia A et al.; Acinetobacter baumannii, mainly biotype 9, is an important nosocomial opportunist pathogen in Chile and other countries . The biological basis of its virulence and prevalence is still unknown . As lipopolysaccharide (LPS) is often associated with virulence, some biological properties of purified LPS from seven nosocomial isolates, comprising four isolates of A . baumannii biotype 9, two isolates of biotype 8 and one isolate of biotype 1, were investigated . LPS was extracted and purified from each isolate by the hot phenol-water method, and its ability to elicit a mitogenic response and to induce the synthesis of a tumour necrosis factor (TNF-alpha) in mouse spleen cells was determined . Activity was evaluated in vivo by determining the splenic index in comparison with LPS from Salmonella Typhimurium . All seven LPS samples were mitogenic on the basis of cellular proliferation experiments and six induced synthesis of TNF-alpha . Similar results were obtained in in-vivo experiments in which LPS induced spleen cell growth, as shown by determination of the splenic index . These results suggest that the LPS of A . baumannii might contribute to the pathogenic properties of this species.

FEMS Microbiol Lett, 1999 Apr 15, 173(2), 453 - 7
Comparison of the electrooptical properties and specific respiratory activity of Acinetobacter calcoaceticum A-122; Ignatov OV et al.; The electrooptical (EO) properties of a cell suspension and the specific respiratory activity of cells towards p-nitrophenol (PNP) were compared during PNP metabolism in Acinetobacter calcoaceticum strain A-122 . The frequency dependence of the suspension's turbidity changes due to cellular orientation (orientational spectra) at frequencies of an orienting electric field of 10-10,000 kHz was determined . Orientational spectral changes observed during PNP incubation of the cells were followed over the range of 10-502 kHz . There were linear relationships between the magnitude of the EO effect at a 502-kHz frequency and the concentration of PNP over the range of 0.1-0.8 mM, and between the specific respiratory activity of the cells and the concentration of PNP over the range of 0.1-1.0 mM . The knowledge gained from these studies suggests a direct relationship between alterations in the cellular EO properties and PNP metabolism.

Clin Diagn Lab Immunol, 1999 May, 6(3), 323 - 9
Identification of Acinetobacter baumannii strains with monoclonal antibodies against the O antigens of their lipopolysaccharides; Pantophlet R et al.; Despite the emergence of Acinetobacter baumannii strains as nosocomial pathogens, simple methods for their phenotypic identification are still unavailable . Murine monoclonal antibodies specific for the O-polysaccharide moiety of the lipopolysaccharide (LPS) of two A . baumannii strains were obtained after immunization with heat-killed bacteria . The monoclonal antibodies were characterized by enzyme immunoassay and by Western and dot blot analyses and were investigated for their potential use for the identification of A . baumannii strains . The antibodies reacted with 46 of the 80 A . baumannii clinical isolates that were investigated, and reactivity was observed with 11 of 14 strains which were isolated during outbreaks in different northwestern European cities; no reactivity was observed with Acinetobacter strains of other genomic species, including the closely related genomic species 1 (Acinetobacter calcoaceticus), 3, and 13 sensu Tjernberg and Ursing, or with other gram-negative bacterial strains . The results show that O-antigen-specific monoclonal antibodies such as the ones described are convenient reagents which can be used to identify Acinetobacter strains in clinical and research laboratories.

J Antimicrob Chemother, 1999 Mar, 43 Suppl A, 31 - 40
The global epidemiology of resistance to ciprofloxacin and the changing nature of antibiotic resistance: a 10 year perspective; Thomson CJ; Many studies have examined the in-vitro activity of ciprofloxacin . The results are for the most part encouraging but we must guard against complacency . Levels of ciprofloxacin resistance vary geographically, while some predictably difficult-to-treat organisms such as Pseudomonas aeruginosa, Staphylococcus aureus and Acinetobacter baumannii present challenges globally . The emergence of resistance in species previously exquisitely sensitive to ciprofloxacin, such as Neisseria gonorrhoeae, in countries associated with 'pirate' production and indiscriminate use of antimicrobials represents a major challenge . Ciprofloxacin continues to show excellent activity against Haemophilus influenzae and Moraxella catharralis . In general, ciprofloxacin shows good activity against Enterobacteriaceae although the emergence of reduced susceptibility and, sometimes, quinolone resistance in multi-resistant isolates should be noted.

Scand J Infect Dis, 1998, 30(6), 585 - 9
Central venous catheter-related bacteraemia in burn patients; Lesseva M; This study aimed to establish the incidence, significance and microbial aetiology of catheter-related bacteraemia (CRB) in burn patients treated in the Sofia Burns Centre, Bulgaria . During the period 1993-97, 1,346 central venous catheters (CVCs) from 1183 burn patients were investigated . Bacterial growth was found in 367 CVCs . Of a total of 675 bacteraemic episodes registered during the study period, 132 were catheter-related (19.5% of all bacteraemic episodes in 6.6% of all patients) . Generalized burn infections were responsible for 29.5% of the bacteraemic episodes in 9.9% of the patients . The main pathogens isolated in cases of CRB were Staphylococcus aureus (84/132), coagulase-negative staphylococci (CNS) (20/132) and Acinetobacter spp . (18/132) . The incidence of S . aureus was considerably higher than that of CNS and Acinetobacter spp . A total of 11 patients with CRB died . Contaminated CVCs were the second most common cause of bacteraemia in burn patients, after generalized wound infection . S . aureus and Acinetobacter spp . were equally important as causes of systemic infection . We conclude that careful management of CVCs, prevention and subsequent treatment of CRB are of great importance for a favourable outcome in burn patients.

APMIS, 1999 Feb, 107(2), 257 - 62
Antibiotic susceptibility of blood culture isolates after nearly two decades with netilmicin and ampicillin in neonatal septicaemia; Ronnestad A et al.; The aim of the study was to investigate the in vitro antibiotic susceptibility of blood culture isolates after almost 20 years with ampicillin and methicillin as empirical treatment for neonatal septicaemia . All blood culture isolates and their antibiograms obtained in a single tertiary neonatal intensive care unit from 1 January 1989 to 31 December 1994 were reviewed . Two hundred and six blood cultures from 181 infants containing 223 bacterial and 11 fungal isolates were identified during 4416 admissions . Fifteen (6.7%) of the bacterial isolates were resistant to ampicillin and netilmicin . Fourteen per cent of the staphylococcal spp . were susceptible to penicillin while more than 90% were susceptible to netilmicin . The coagulase-negative staphylococci (CONS) were resistant to netilmicin, methicillin and gentamicin in 12%, 49% and 65%, respectively . Eighty-nine per cent of the methicillin-resistant CONS were susceptible to netilmicin as opposed to 17% to gentamicin (p<0.001) . Except for one strain of Acinetobacter sp., all Gram-negative bacteria were susceptible to netilmicin . Our data show that the ampicillin-netilmicin combination still provides a high in vitro coverage (93%) against bacteria identified in blood cultures from newborns in our unit . Netilmicin has a significantly better in vitro effectiveness against CONS than gentamicin.

Appl Environ Microbiol, 1999 May, 65(5), 2041 - 8
Adhesion of acinetobacter venetianus to diesel fuel droplets studied with In situ electrochemical and molecular probes
Baldi F, Ivosevic N, Minacci A, Pepi M, Fani R, Svetlicic V V, utic V V.
The adhesion of a recently described species, Acinetobacter venetianus VE-C3 (F . Di Cello, M . Pepi, F . Baldi, and R . Fani, Res . Microbiol . 148:237-249, 1997), to diesel fuel (a mixture of C12 to C28 n-alkanes) and n-hexadecane was studied and compared to that of Acinetobacter sp . strain RAG-1, which is known to excrete the emulsifying lipopolysaccharide, emulsan . Oxygen consumption rates, biomass, cell hydrophobicity, electrophoretic mobility, and zeta potential were measured for the two strains . The dropping-mercury electrode (DME) was used as an in situ adhesion sensor . In seawater, RAG-1 was hydrophobic, with an electrophoretic mobility (&mgr;) of -0.38 x 10(-8) m2 V-1 s-1 and zeta potential (zeta) of -4.9 mV, while VE-C3 was hydrophilic, with &mgr; of -0.81 x 10(-8) m2 V-1 s-1 and zeta of -10.5 mV . The microbial adhesion to hydrocarbon (MATH) test showed that RAG-1 was always hydrophobic whereas the hydrophilic VE-C3 strain became hydrophobic only after exposure to n-alkanes . Adhesion of VE-C3 cells to diesel fuel was partly due to the production of capsular polysaccharides (CPS), which were stained with the lectin concanavalin A (ConA) conjugated to fluorescein isothiocyanate and observed in situ by confocal microscopy . The emulsan from RAG-1, which was negative to ConA, was stained with Nile Red fluorochrome instead . Confocal microscope observations at different times showed that VE-C3 underwent two types of adhesion: (i) cell-to-cell interactions, preceding the cell adhesion to the n-alkane, and (ii) incorporation of nanodroplets of n-alkane into the hydrophilic CPS to form a more hydrophobic polysaccharide-n-alkane matrix surrounding the cell wall . The incorporation of n-alkanes as nanodroplets into the CPS of VE-C3 cells might ensure the partitioning of the bulk apolar phase between the aqueous medium and the outer cell membrane and thus sustain a continuous growth rate over a prolonged period.

J Antimicrob Chemother, 1999 Mar, 43(3), 373 - 8
A surveillance study of antimicrobial resistance of gram-negative bacteria isolated from intensive care units in eight hospitals in Turkey; Gunseren F et al.; This study was carried out with the participation of eight hospitals in Turkey to determine the frequency of gram-negative bacteria isolated in intensive care units (ICU) and to compare their resistance rates to selected antibiotics . Aerobic gram-negative bacteria isolated from ICUs during 1996 were studied . Antibiotic susceptibilities to imipenem, ceftazidime, ceftazidime-clavulanate, ceftriaxone, cefotaxime, cefepime, cefodizime, cefuroxime, piperacillin/tazobactam, amoxycillin-clavulanate, gentamicin, amikacin and ciprofloxacin were determined by Etest . A total of 748 isolates were obtained from 547 patients . The majority of organisms were isolated from the respiratory (38.8%) and urinary tracts (30.9%) . Pseudomonas spp . were the most frequently isolated gram-negative species (26.8%), followed by Klebsiella spp . (26.2%) . Escherichia coli, Acinetobacter spp . and Enterobacter spp . were the other commonly isolated organisms . High resistance rates were observed for all antibiotics studied . Imipenem appeared to be the most active agent against the majority of isolates . Although resistance rates exceeded 50%, ciprofloxacin, cefepime and amikacin were found to be relatively effective . Extended-spectrum beta-lactamase (ESBL) production appeared to be a major mechanism of resistance to beta-lactam antibiotics . In contrast to ceftazidime-clavulanate, piperacillin/tazobactam showed poor activity against organisms thought to produce ESBL, suggesting the presence of an enzyme resistant to tazobactam action . This study has yielded high rates of resistance in aerobic gram-negative isolates from ICUs in Turkey . High resistance rates to all the other antibacterials studied leave imipenem as the only reliable agent for the empirical treatment of ICU infections in Turkey.

Med Dosw Mikrobiol, 1998, 50(3-4), 229 - 37
{Adhesins of Acinetobacter strains}; Fleischer M et al.; One of the important factors contributing to the pathogenicity of bacteria is the presence of adhesins on cell surface, which facilitate colonisation in the macroorganism . The presence and type of adhesins occurring in four species of the genus Acinetobacter: A . baumannii (184), A . junii (59), A . lwoffii (65) and A . haemolyticus (22) was determined by haemagglutination test with a 3% suspension of fresh, tannic acid-treated of guinea pig, cow and human group O and AB erythrocytes, with or without the addition of one of sugar inhibitors (D-mannose, alpha-methylmannopyranoside, D-galactose-N-acetyl-D-glucosamine, L-fucose and D-ribose) . In strains from all species, adhesines of the mannose-resistant (MR) type dominated . The mannose-sensitive (MS) type was present solely on the surface of one A . lwoffii strains . A . baumannii (36), A . junii (8), A . lwoffii (11) and A . haemolyticus (4) exhibited mannose-resistant hemagglutination in relation to fresh erythrocytes and that reaction was restrained by D-galactose, D-galactose and L-fucose (no other inhibitor used restrained it) . The results achieved prove that cell adhesines other than those of MR type must be present on the cell surface . Additional adhesines occurred mainly in strains isolated from the respiratory and urinary tract infection simples, but were not found in isolates from blood cultures.

Gene, 1999 Apr 16, 230(2), 277 - 86
Cloning and sequence analysis of the lipase and lipase chaperone-encoding genes from Acinetobacter calcoaceticus RAG-1, and redefinition of a proteobacterial lipase family and an analogous lipase chaperone family; Sullivan ER et al.; The genes encoding the lipase (LipA) and lipase chaperone (LipB) from Acinetobacter calcoaceticus RAG-1 were cloned and sequenced . The genes were isolated from a genomic DNA library by complementation of a lipase-deficient transposon mutant of the same strain . Transposon insertion in this mutant and three others was mapped to a single site in the chaperone gene . The deduced amino acid (aa) sequences for the lipase and its chaperone were found to encode mature proteins of 313 aa (32.5kDa) and 347 aa (38.6kDa), respectively . The lipase contained a putative leader sequence, as well as the conserved Ser, His, and Asp residues which are known to function as the catalytic triad in other lipases . A possible trans-membrane hydrophobic helix was identified in the N-terminal region of the chaperone . Phylogenetic comparisons showed that LipA, together with the lipases of A . calcoaceticus BD413, Vibrio cholerae El Tor, and Proteus vulgaris K80, were members of a previously described family of Pseudomonas and Burkholderia lipases . This new family, which we redefine as the Group I Proteobacterial lipases, was subdivided into four subfamilies on the basis of overall sequence homology and conservation of residues which are unique to the subfamilies . LipB, moreover, was found to be a member of an analogous family of lipase chaperones . We propose that the lipases produced by P . fluorescens and Serratia marcescens, which comprise a second sequence family, be referred to as the Group II Proteobacterial lipases . Evidence is provided to support the hypothesis that both the Group I and Group II families have evolved from a combination of common descent and lateral gene transfer.

Jpn J Med Sci Biol, 1998 Nov, 51(1), 25 - 33
Influence of iron on growth and extracellular products of Acinetobacter baumannii; Goel VK et al.; Iron is an important nutrient required by bacteria for optimal growth . Acquisition of iron from the host where iron is restricted is an important mediator of bacterial pathogenesis . In iron deplete chemically defined medium (CDM-Fe) growth of Acinetobacter baumannii was restricted as compared to iron replete medium (CDM + Fe) . Bacteria developed four high molecular weight outer membrane proteins (OMPs) of 88, 84, 80 and 77 kDa in CDM-Fe medium which were absent in CDM + Fe medium, and are known iron regulated outer membrane proteins (IROMPs) . A . baumannii secreted siderophores extracellularly into the medium which act as iron chelators which had been demonstrated in the supernatants of CDM-Fe media . The siderophore was of catechol type . This shows that A . baumannii under iron restricted conditions express IROMPs along with production of catechol type siderophore in order to acquire iron from the external milieu.

Syst Appl Microbiol, 1999 Feb, 22(1), 59 - 67
Phylogenetic analysis of proteolytic Acinetobacter strains based on the sequence of genes encoding aminoglycoside 6'-N-acetyltransferases; Rudant E et al.; The sequence of seven aac(6')-I genes encoding aminoglycoside 6'-N-acetyltransferases from proteolytic Acinetobacter strains including genomic species 14, 15, 16, and 17 and from ungrouped proteolytic strains 631, 640, and BM2722 was determined . Pulsed-field gel electrophoresis of genomic DNA of these strains and of Acinetobacter sp . 6 CIP A165 digested with SfiI followed by hybridization with rRNA and aac(6')-I specific probes indicated that these genes were located in the chromosome . Phylogenetic analysis of the genes indicated that aac(6')-I of A . baumannii, Acinetobacter ungrouped strain 631, and Acinetobacter sp . 16 formed a cluster (91.5 to 92.3% identity) whereas aac(6')-I of Acinetobacter sp . 15, sp . 17, and Acinetobacter ungrouped strain BM2722 formed another cluster (90.7 to 94.6% identity) . A third cluster was constituted by A . haemolyticus and Acinetobacter sp . 6 (83.6% identity) . The phylogeny drawn from aac(6')-I sequences was consistent with that based on DNA-DNA hybridization and phenotype comparison . The aac(6')-I genes were all species specific except for aac(6')-Ih located in a 13.7-kb non conjugative plasmid from A . baumannii BM2686 . We conclude that aac(6')-I genes may be suitable for identification at the species level and for analysis of the phylogenetic relationships of Acinetobacter.

Appl Environ Microbiol, 1999 Apr, 65(4), 1675 - 80
Phenotypic expression of PCR-generated random mutations in a Pseudomonas putida gene after its introduction into an Acinetobacter chromosome by natural transformation; Kok RG et al.; Localized sets of random point mutations generated by PCR amplification can be transferred efficiently to the chromosome of Acinetobacter ADP1 (also known as strain BD413) by natural transformation . The technique does not require cloning of PCR fragments in plasmids: PCR-amplified DNA fragments are internalized by cells and directly incorporated into their genomes by homologous recombination . Previously such procedures for random mutagenesis could be applied only to Acinetobacter genes affording the selection of mutant phenotypes . Here we describe the construction of a vector and recipient that allow for mutagenesis, recovery, and expression of heterologous genes that may lack a positive selection . The plasmid carries an Acinetobacter chromosomal segment interrupted by a multiple cloning site next to a kanamycin resistance marker . The insertion of heterologous DNA into the multiple cloning site prepares the insert as a target for PCR mutagenesis . PCR amplifies the kanamycin resistance marker and a flanking region of Acinetobacter DNA along with the insert of heterologous DNA . Nucleotide sequence identity between the flanking regions and corresponding chromosomal segments in an engineered Acinetobacter recipient allows homologous recombination of the PCR-amplified DNA fragments into a specific chromosomal docking site from which they can be expressed . The recipient strain contains only a portion of the kanamycin resistance gene, so donor DNA containing both this gene and the mutagenized insert can be selected by demanding growth of recombinants in the presence of kanamycin . The effectiveness of the technique was demonstrated with the relatively GC-rich Pseudomonas putida xylE gene . After only one round of PCR amplification (35 cycles), donor DNA produced transformants of which up to 30% carried a defective xylE gene after growth at 37 degrees C . Of recombinant clones that failed to express xylE at 37 degrees C, about 10% expressed the gene when grown at 22 degrees C . The techniques described here could be adapted to prepare colonies with an altered function in any gene for which either a selection or a suitable phenotypic screen exists.

Appl Environ Microbiol, 1999 Apr, 65(4), 1658 - 61
Effects of surfactant mixtures, including Corexit 9527, on bacterial oxidation of acetate and alkanes in crude oil; Bruheim P et al.; Mixtures of nonionic and anionic surfactants, including Corexit 9527, were tested to determine their effects on bacterial oxidation of acetate and alkanes in crude oil by cells pregrown on these substrates . Corexit 9527 inhibited oxidation of the alkanes in crude oil by Acinetobacter calcoaceticus ATCC 31012, while Span 80, a Corexit 9527 constituent, markedly increased the oil oxidation rate . Another Corexit 9527 constituent, the negatively charged dioctyl sulfosuccinate (AOT), strongly reduced the oxidation rate . The combination of Span 80 and AOT increased the rate, but not as much as Span 80 alone increased it, which tentatively explained the negative effect of Corexit 9527 . The results of acetate uptake and oxidation experiments indicated that the nonionic surfactants interacted with the acetate uptake system while the anionic surfactant interacted with the oxidation system of the bacteria . The overall effect of Corexit 9527 on alkane oxidation by A . calcoaceticus ATCC 31012 thus seems to be the sum of the independent effects of the individual surfactants in the surfactant mixture . When Rhodococcus sp . strain 094 was used, the alkane oxidation rate decreased to almost zero in the presence of a mixture of Tergitol 15-S-7 and AOT even though the Tergitol 15-S-7 surfactant increased the alkane oxidation rate and AOT did not affect it . This indicated that there was synergism between the two surfactants rather than an additive effect like that observed for A . calcoaceticus ATCC 31012.

Appl Environ Microbiol, 1999 Apr, 65(4), 1477 - 82
Microbiology of the oil fly, Helaeomyia petrolei; Kadavy DR et al.; Helaeomyia petrolei larvae isolated from the asphalt seeps of Rancho La Brea in Los Angeles, Calif., were examined for microbial gut contents . Standard counts on Luria-Bertani, MacConkey, and blood agar plates indicated ca . 2 x 10(5) heterotrophic bacteria per larva . The culturable bacteria represented 15 to 20% of the total population as determined by acridine orange staining . The gut itself contained large amounts of the oil, had no observable ceca, and maintained a slightly acidic pH of 6.3 to 6.5 . Despite the ingestion of large amounts of potentially toxic asphalt by the larvae, their guts sustained the growth of 100 to 1,000 times more bacteria than did free oil . All of the bacteria isolated were nonsporeformers and gram negative . Fourteen isolates were chosen based on representative colony morphologies and were identified by using the Enterotube II and API 20E systems and fatty acid analysis . Of the 14 isolates, 9 were identified as Providencia rettgeri and 3 were likely Acinetobacter isolates . No evidence was found that the isolates grew on or derived nutrients from the asphalt itself or that they played an essential role in insect development . Regardless, any bacteria found in the oil fly larval gut are likely to exhibit pronounced solvent tolerance and may be a future source of industrially useful, solvent-tolerant enzymes.

Antimicrob Agents Chemother, 1999 Apr, 43(4), 782 - 8
In vitro antibacterial properties of pexiganan, an analog of magainin; Ge Y et al.; Pexiganan, a 22-amino-acid antimicrobial peptide, is an analog of the magainin peptides isolated from the skin of the African clawed frog . Pexiganan exhibited in vitro broad-spectrum antibacterial activity when it was tested against 3,109 clinical isolates of gram-positive and gram-negative, anaerobic and aerobic bacteria . The pexiganan MIC at which 90% of isolates are inhibited (MIC90) was 32 micrograms/ml or less for Staphylococcus spp., Streptococcus spp., Enterococcus faecium, Corynebacterium spp., Pseudomonas spp., Acinetobacter spp., Stenotrophomonas spp., certain species of the family Enterobacteriaceae, Bacteroides spp., Peptostreptococcus spp., and Propionibacterium spp . Comparison of the MICs and minimum bactericidal concentrations (MBCs) of pexiganan for 143 isolates representing 32 species demonstrated that for 92% of the isolates tested, MBCs were the same or within 1 twofold difference of the MICs, consistent with a bactericidal mechanism of action . Killing curve analysis showed that pexiganan killed Pseudomonas aeruginosa rapidly, with 10(6) organisms/ml eliminated within 20 min of treatment with 16 micrograms of pexiganan per ml . No evidence of cross-resistance to a number of other antibiotic classes was observed, as determined by the equivalence of the MIC50s and the MIC90s of pexiganan for strains resistant to oxacillin, cefazolin, cefoxitin, imipenem, ofloxacin, ciprofloxacin, gentamicin, and clindamicin versus those for strains susceptible to these antimicrobial agents . Attempts to generate resistance in several bacterial species through repeated passage with subinhibitory concentrations of pexiganan were unsuccessful . In conclusion, pexiganan exhibits properties in vitro which make it an attractive candidate for development as a topical antimicrobial agent.

Biotechnol Bioeng, 1999 Feb 5, 62(3), 311 - 6
Effect of oxygen transfer on lipase production by Acinetobacter radioresistens; Chen JY et al.; The influence of oxygen on alkaline lipase production by Acinetobacter radioresistens was studied under two operating modes: controlled dissolved oxygen (DO) concentration and controlled aeration rate . Compared with cell growth, the lipase production depended more extensively on oxygen . The intrinsic factor determining cell growth and lipase production was oxygen transfer rate (OTR) rather than DO concentration . Improvements in OTR, either by aeration or agitation, resulted in an increase in lipase yield and/or a reduction in fermentation time . The formation of A . radioresistens lipase could be described by a mixed-growth-associated model, and the enzyme was mainly a growth-associated product . The overall productivity for the lipase, which depended more strongly on agitation than aeration, could be related with kLa . DO concentration could not be employed in this correlation, though it has been useful as a criterion for ensuring no oxygen limitation in an aerobic fermentation .

Yonsei Med J, 1998 Dec, 39(6), 569 - 77
Korean Nationwide Surveillance of Antimicrobial Resistance of bacteria in 1997; Chong Y et al.; Antimicrobial-resistant bacteria are known to be prevalent in tertiary-care hospitals in Korea . Twenty hospitals participated to this surveillance to determine the nationwide prevalence of resistance bacteria in 1997 . Seven per cent and 26% of Escherichia coli and Klebsiella pneumoniae were resistant to 3rd-generation cephalosporin . Increased resistance rates, 19% of Acinetobacter baumannii to ampicillin/sulbactam, and 17% of Pseudomonas aeruginoa to imipenem, were noted . The resistance rate to fluoroquinolone rose to 24% in E . coli, 56% in A . baumannii and 42% in P . aeruginosa . Mean resistance rates were similar in all hospital groups: about 17% of P . aeruginosa to imipenem, 50% of Haemophilus influenzae to ampicillin, 70% of Staphylococcus aureus to methicillin, and 70% of pneumococci to penicillin . In conclusion, nosocomial pathogens and problem resistant organisms are prevalent in smaller hospitals too, indicating nosocomial spread is a significant cause of the increasing prevalence of resistant bacteria in Korea.

J Spinal Cord Med, 1998 Oct, 21(4), 342 - 7
Does refrigeration of urine alter culture results in hospitalized patients with neurogenic bladders?
Horton JA 3rd, Kirshblum SC, Linsenmeyer TA, Johnston M, Rustagi A.
A prospective, blinded study of 40 hospitalized spinal cord injured (SCI) patients was conducted to evaluate the effects of refrigeration on urinalysis and culture results . Urine samples were divided, with one aliquot examined within 4 hours and the other after 24 hours of refrigeration . Comparisons using Wilcoxon Signed Rank analysis showed no significant difference between fresh and refrigerated samples in white blood cell (WBC) count (z = -0.353, p = 0.724), number of bacteria (z = -0.772, p = 0.440), leukocytes (z = -0.277, p = 0.782), or colony counts of E . fecalis, E . coli, Citrobacter, Pseudomonas, Streptococcus, Yeast, or Acinetobacter (z = -1.00, p = 0.317; z = 0.00, p = 1.0; z = 0.00, p = 1.0; z = 0.00, p = 1.0; z = -1.00, p = 0.317; z = 0.00, p = 1.0; z = 0.00, p = 1.0, respectively) . A statistically significant difference between fresh and refrigerated samples was found with "mixed" organisms (z = -2.565, p = 0.010) and a difference approaching significance was found with Staph aureus (z = -1.841, p = 0.066), both with colony counts of less than 50 k . No changes in cultures or colony counts occurred following refrigeration that would have resulted in altered treatment regimens . This study indicates that refrigeration of urine samples for up to 24 hours in the hospital setting rarely causes changes in identified organism type and causes no clinically significant changes in urinalysis or urine culture results in SCI patients.

Res Microbiol, 1999 Jan-Feb, 150(1), 69 - 73
Oil-degrading Acinetobacter strain RAG-1 and strains described as 'Acinetobacter venetianus sp . nov.' belong to the same genomic species; Vaneechoutte M et al.; Acinetobacter strain RAG-1 (ATCC 31012) is an industrially important strain which has been extensively characterized with respect to its growth an hydrocarbons and its production of a high molecular mass bioemulsifier, emulsan . Although RAG-1 has been investigated in detail for specific biochemical characteristics, its taxonomic status is uncertain and it is usually referred to as A . lwoffii or A . calcoaceticus sensu lato . However, results obtained by restriction analysis of the amplified rDNA and subsequently substantiated by DNA-DNA hybridization, partial 16S rDNA nucleotide sequence comparison and biochemical characterization indicate that RAG-1 belongs to the genomic species recently described as 'A . venetianus' . Furthermore, these data confirm that 'A . venetianus' constitutes a new and distinct genomic species within the genus Acinetobacter.

Antibiot Khimioter, 1999, 44(1), 20 - 2
{Use of pefloxacin in the treatment of patients with purulent wounds of soft tissues}; Blatun LA et al.; Pefloxacin was used in the treatment of 25 patients with wound infection in a dose of 400 mg orally twice a day for 10-12 days . As the monotherapy it was applied to 15 patients . 7 patients with clinical signs of non-clostridial anaerobic infection were treated with pefloxacin in combination with intravenous metronidazole . Pefloxacin was highly efficient in 96 per cent of the cases with extensive posttraumatic purulent wounds with and without bone affection, acute purulent wounds of the soft tissue, purulent wounds of the soft tissues in diabetic patients, trophic or decubitus ulcer . 266 clinical isolates of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Proteus mirabilis, Enterobacter spp . and Acinetobacter spp, were tested and 75 to 100 per cent of them was shown to be susceptible to pefloxacin and ciprofloxacin . At the same time the isolates of Pseudomonas aeruginosa and Klebsiella spp . were more susceptible to ciprofloxacin . The pathogen eradication and eradication with superinfection in the cases treated with pefloxacin amounted to 92 per cent . The drug tolerance was good . No clinically significant adverse events were recorded.

Br J Haematol, 1999 Mar, 104(3), 560 - 8
Infections in adults undergoing unrelated donor bone marrow transplantation; Williamson EC et al.; This study retrospectively reviews infections over a 7-year period in 60 consecutive adults (median age 25 years) undergoing their first unrelated donor bone marrow transplant (UD-BMT) . T-cell depletion was employed in 93% . More than half the patients had one or more severe, potentially life-threatening, infections . There was a high incidence of invasive fungal infections (Aspergillus 17, Candida four), despite the use of itraconazole or amphotericin prophylaxis . Ten Aspergillus infections occurred beyond 100 d . Two patients (11%) with invasive aspergillosis survived . Clustering of infections was noted, with invasive fungal infections significantly associated with bacteraemias (OR 3.73, P=0.06) and multiple viral infections (OR 4.25, P=0.05) . There were 21 severe viral infections in 16 patients, with CMV disease occurring in four patients only; viral pneumonitis was predominantly due to 'community respiratory' viruses . Most early bacteraemias (68%) were due to Gram-positive organisms . The majority of episodes of Gram-negative sepsis were caused by non-fastidious non-fermentative bacteria, such as Pseudomonas spp . and Acinetobacter spp., historically regarded as organisms of low pathogenicity . In patients with successful engraftment and minimal graft-versus-host disease, late infections suggestive of continued immune dysfunction (shingles, recurrent lower respiratory infections, Salmonella enteritis and extensive warts) were common.

Chest, 1999 Mar, 115(3 Suppl), 28S - 33S
Nosocomial pneumonia in the ICU--year 2000 and beyond; Bowton DL; Diagnostic and treatment strategies in ICU patients with ventilator-associated pneumonia (VAP) remain controversial, largely because of the paucity of well-controlled comparison trials using clinically important end points . Recent studies indicating that early appropriate antibiotic therapy significantly lowers mortality underscore the urgent need for well-designed comparative trials . When quantitatively cultured, bronchial specimens obtained by noninvasive techniques may provide clinically useful information and avoid the higher costs and risks of invasive bronchoscopic diagnostic techniques . Previous antibiotic use before onset of nosocomial pneumonia raises the likelihood of infection with highly virulent organisms, such as Pseudomonas aeruginosa and Acinetobacter sp . Thus, the empiric antibiotic regimen should be active against these Gram-negative pathogens as well as other common Gram-negative and Gram-positive causative organisms . Promising preventive modalities for nosocomial VAP include use of a semirecumbent position, endotracheal tubes that allow continuous aspiration of secretions, and heat and moisture exchangers . Rotating their standard empiric antibiotic regimens and restricting the use of third-generation cephalosporins as empiric therapy may help hospitals reduce the incidence of nosocomial pneumonia caused by resistant Gram-negative pathogens.

Curr Microbiol, 1999 Apr, 38(4), 250 - 5
Conversion of unsaturated fatty acids by bacteria isolated from compost; Kaneshiro T et al.; A compost mixture amended with soybean oil was enriched in microorganisms that transformed unsaturated fatty acids (UFAs) . When oleic acid or 10-ketostearic acid was the selective fatty acid, Sphingobacterium thalpophilum (NRRL B-23206, NRRL B-23208, NRRL B-23209, NRRL B-23210, NRRL B-23211, NRRL B-23212), Acinetobacter spp . (NRRL B-23207, NRRL B-23213), and Enterobacter cloacae (NRRL B-23264, NRRL B-23265, NRRL B-23266) represented isolates that produced either hydroxystearic acid, ketostearic acid, or incomplete decarboxylations . When ricinoleic (12-hydroxy-9-octadecenoic) acid was the selective UFA, Enterobacter cloacae (NRRL B-23257, NRRL B-23267) and Escherichia sp . (NRRL B-23259) produced 12-C and 14-C homologous compounds, and Pseudomonas aeruginosa (NRRL B-23256, NRRL B-23260) converted ricinoleate to a trihydroxyoctadecenoate product . Also, various Enterobacter, Pseudomonas, and Serratia spp . appeared to decarboxylate linoleate substrate incompletely . These saprophytic, compost bacteria were aerobic or facultative anaerobic Gram-negative and decomposed UFAs through decarboxylation, hydroxylation, and hydroperoxidation mechanisms.

FEBS Lett, 1999 Feb 19, 445(1), 137 - 43
On the binding of ATP to the autophosphorylating protein, Ptk, of the bacterium Acinetobacter johnsonii; Doublet P et al.; The autophosphorylating protein, Ptk, of the bacterium Acinetobacter johnsonii was overproduced, purified to homogeneity and assayed for ATP binding by using the nucleotide analog 5'-p-fluorosulfonylbenzoyl adenosine . The ATP binding site of this bacterial autophosphorylating protein was found to be different from that generally used by eukaryotic protein kinases . It consists of two amino acid sequences that closely resemble the Walker motifs A and B . This observation was confirmed by site-directed mutagenesis experiments which showed, in addition, that the ATP molecule bound to these motifs is effectively employed by the bacterial protein to autophosphorylate on tyrosine . It is concluded that even though the overall autophosphorylation reaction is similar in eukaryotic and prokaryotic proteins, the mechanism involved is likely different.

Protein Eng, 1999 Jan, 12(1), 63 - 70
Engineering a chimeric pyrroloquinoline quinone glucose dehydrogenase: improvement of EDTA tolerance, thermal stability and substrate specificity; Yoshida H et al.; An engineered Escherichia coli PQQ glucose dehydrogenase (PQQGDH) with improved enzymatic characteristics was constructed by substituting and combining the gene-encoding protein regions responsible for EDTA tolerance, thermal stability and substrate specificity . The protein region responsible for complete EDTA tolerance in Acinetobacter calcoaceticus, which is recognized as the indicator of high stability in co-factor binding, was elucidated . The region is located between 32 and 59% from the N-terminus of A . calcoaceticus PQQGDH(A27 region) and also corresponds to the same position from 32 to 59% from the N-terminus in E . coli PQQGDH, though E . coli PQQGDH is EDTA sensitive . We previously reported that the C-terminal 3% region of A . calcoaceticus (A3 region) played an important role in the increase of thermal stability, and that His775Asn substitution in E . coli PQQGDH resulted in an increase in the substrate specificity of E . coli PQQGDH towards glucose . Based on these findings, chimeric and/or mutated PQQGDHs, E97A3 H775N, E32A27E41 H782N, E32A27E38A3 and E32A27E38A3 H782N were constructed to investigate the compatibility of two protein regions and one amino acid substitution . His775 substitution to Asn corresponded to His782 substitution to Asn (H782N) in chimeric enzymes harbouring the A27 region . Since all the chimeric PQQGDHs harbouring the A27 region were EDTA tolerant, the A27 region was found to be compatible with the other region and substituted amino acid responsible for the improvement of enzymatic properties . The contribution of the A3 region to thermal stability complemented the decrease in the thermal stability due to the His775 or His782 substitution to Asn . E32A27E38A3 H782N, which harbours all the above mentioned three regions, showed improved EDTA tolerance, thermal stability and substrate specificity . These results suggested a strategy for the construction of a semi-artificial enzyme by substituting and combining the gene-encoding protein regions responsible for the improvement of enzyme characteristics . The characteristics of constructed chimeric PQQGDH are discussed based on the predicted model, beta-propeller structure.

J Antimicrob Chemother, 1998 Dec, 42(6), 793 - 802
Efficacy of sulbactam alone and in combination with ampicillin in nosocomial infections caused by multiresistant Acinetobacter baumannii; Corbella X et al.; From March 1995 to March 1997, sulbactam was prospectively evaluated in patients with non-life-threatening multiresistant Acinetobacter baumannii infections . During this period, 47 patients were treated with sulbactam; of them, five were excluded because they had received < or =48 h of sulbactam therapy . A total of 42 patients, 27 males and 15 females with a mean age of 60+/-15 years, were finally evaluated . Infections were as follows: surgical wound, 19; tracheobronchitis, 12; urinary tract, 7; catheter-related bacteraemia, 2; and pneumonia, 2 . Eighteen patients received intravenous sulbactam alone (1 g every 8 h) and 24 patients received intravenous sulbactam/ampicillin (1 g:2 g every 8 h) with no major adverse effects . Of the 42 patients, 39 improved or were cured and showed A . baumannii eradication and one patient had persistence of wound infection after 8 days of sulbactam/ampicillin requiring surgical debridement . Two patients died after 3 days of therapy (one of the deaths was attributable to A . baumannii infection) . The in-vitro activity of the sulbactam/ampicillin combination was by virtue of the antimicrobial activity exhibited by sulbactam . Killing curves showed that sulbactam was bacteriostatic; no synergy was observed between ampicillin and sulbactam . Our results indicate that sulbactam may prove effective for non-life-threatening A . baumannii infections . Its role in the treatment of severe infections is unknown . However, the current formulation of sulbactam alone may allow its use at higher doses and provide new potential synergic combinations, particularly for those infections by A . baumannii resistant to imipenem.

Rev Med Chil, 1998 Oct, 126(10), 1183 - 8
{Adherence of Acinetobacter baumannii to rat tracheal tissue}; Ruiz M et al.; BACKGROUND: Acinetobacter baumannii is an important nosocomial pathogen whose virulence factors have not been fully elucidated . AIM: To study the adherence and hemagglutinating capacity of several biotypes of Acinetobacter baumannii . MATERIAL AND METHODS: Thirty nine strains of Acinetobacter baumannii isolated from hospitalized patients were studied . The adherence of these strains to small pieces of rat tracheal tissue was studied . Additionally, their ability to hemagglutinate human erythrocytes and the effect of D-mannose and D-galactose on the adherence and hemagglutinating capacity was assessed . Transmission electron microscopy of strains was performed looking for the presence of fimbriae . RESULTS: All strains exhibited adherence to tissues . All strains had also D-mannose and D-galactose resistant hemagglutinating ability . Fimbriae were found in Acinetobacter baumannii and E coil cells . CONCLUSIONS: Adherence of Acinetobacter baumannii to rat tracheal tissue, apparently not related to the presence of fimbriae, may be a virulence mechanism of this bacterium.

Clin Infect Dis, 1999 Jan, 28(1), 59 - 66
Risk factors for nosocomial bloodstream infections due to Acinetobacter baumannii: a case-control study of adult burn patients; Wisplinghoff H et al.; Risk factors for Acinetobacter baumannii bloodstream infection (BSI) were studied in patients with severe thermal injury in a burn intensive care unit where A . baumannii was endemic . Of 367 patients hospitalized for severe thermal injury during the study period, 29 patients with nosocomial A . baumannii BSI were identified (attack rate, 7.9%) . Cases were compared with 58 matched controls without A . baumannii BSI . The overall mortality rate was 31% among cases and 14% among controls; only two deaths (7%) were considered directly related to A . baumannii BSI . Molecular typing of A . baumannii blood isolates by means of randomly amplified polymorphic DNA analysis and pulsed-field gel electrophoresis revealed the presence of three different strain types . Multivariate analysis showed that female gender (P = .027), total body surface area burn of > 50% (P = .016), prior nosocomial colonization with A . baumannii at a distant site (P = .0002), and use of hydrotherapy (P = .037) were independently associated with the acquisition of A . baumannii BSI in burn patients . These data underscore the need for effective infection control measures for this emerging nosocomial problem.

Clin Infect Dis, 1999 Jan, 28(1), 26 - 30
Acinetobacter bacteremia in Hong Kong: prospective study and review; Siau H et al.; The epidemiological characteristics of 18 patients with acinetobacter bacteremia were analyzed . Patients (mean age, 55.5 years) developed bacteremia after an average of 14.1 days of hospitalization . Fifteen of 16 patients survived bacteremia caused by Acinetobacter baumannii . Cultures of blood from the remaining two patients yielded Acinetobacter lwoffii . Most patients (78%) resided in the general ward, while four patients (22%) were under intensive care . Genotyping by arbitrarily primed polymerase chain reaction analysis and the temporal sequence of isolation were more useful than phenotyping by antimicrobial susceptibility in the determination of the source of bacteremia, and the intravascular catheter was the leading infection source (39% of cases) . The possibility of an association of glucose with the pathogenesis of acinetobacter infection was raised.

Int J Syst Bacteriol, 1999 Jan, 49 Pt 1, 87 - 95
Phylogenetic structures of the genus Acinetobacter based on gyrB sequences: comparison with the grouping by DNA-DNA hybridization; Yamamoto S et al.; The phylogenetic relationships of 49 Acinetobacter strains, 46 of which have previously been classified into 18 genomic species by DNA-DNA hybridization studies, were investigated using the nucleotide sequence of gyrB, the structural gene for the DNA gyrase B subunit . The phylogenetic tree showed linkages between genomic species 1 (Acinetobacter calcoaceticus), 2 (Acinetobacter baumannii), 3 and TU13; genomic species 6, BJ15, BJ16 and BJ17; genomic species 5, BJ13 (synonym of TU14) and BJ14; genomic species 7 (Acinetobacter johnsonii), 10 and 11; and genomic species 8 and 9 . The phylogenetic grouping of Acinetobacter strains based on gyrB genes was almost congruent with that based on DNA-DNA hybridization studies . Consequently, gyrB sequence comparison can be used to resolve the taxonomic positions of bacterial strains at the level of genomic species . However, minor discrepancies existed in the grouping of strains of genomic species 8, 9 and BJ17 . The phylogenetic tree for these strains was reconstructed from the sequence of rpoD, the structural gene for the RNA polymerase sigma 70 factor . The latter tree was 100% congruent with the grouping based on DNA-DNA hybridization . The reliability of DNA-DNA hybridization may be superior to that of sequence comparison of a single protein-encoding gene in resolving closely related organisms since the former method measures the homologies between the nucleotide sequences of total genomic DNAs . Three strains that have not been characterized previously by DNA-DNA hybridization seem to belong to two new genomic species, one including strain ATCC 33308 and the other including strains ATCC 31012 and MBIC 1332.

J Clin Pathol, 1998 Oct, 51(10), 786 - 8
Effect of desiccation on the ultrastructural appearances of Acinetobacter baumannii and Acinetobacter lwoffii; Houang ET et al.; An Acinetobacter baumannii isolate survived desiccation beyond 30 days and an Acinetobacter lwoffii isolate up to 21 days . For both species, desiccation resulted in a significant increase in the proportion of round cells (A baumannii, 40% to 80%; A lwoffii, 51% to 63%) and a significant decrease in rod shaped cells (A baumannii, 58% to 13%; A lwoffii, 46% to 34%) . Electronmicroscopic examination showed that there was also a corresponding significant increase in the cell wall thickness (A baumannii, up to 53%; A lwoffii, up to 26%) . Desiccated A baumannii cells became more electron-dense and had significantly thicker cell walls (x1.3) than those of A lwoffii . Cell wall structures of A baumannii strains with different abilities to resist desiccation deserve further study.

Diagn Microbiol Infect Dis, 1999 Jan, 33(1), 33 - 8
In vitro activity of trovafloxacin against ciprofloxacin-susceptible and -resistant clinical bacterial isolates and assessment of the trovafloxacin disk test; Fuchs PC et al.; A total of 4241 consecutive clinical bacterial isolates from 10 North American medical centers were tested for susceptibility to trovafloxacin . Trovafloxacin was significantly more active than ciprofloxacin against Gram-positive bacteria, Acinetobacter spp., and Stenotrophomonas maltophilia, and resistance to trovafloxacin occurred in these groups only among isolates with high-level resistance (MIC > or = 16 micrograms/mL) to ciprofloxacin . With other species, the two drugs had comparable activity . Concerns about staphylococci and Pseudomonas aeruginosa with trovafloxacin MICs of 2.0 micrograms/mL (the upper end of the susceptible category) are discussed . Results of trovafloxacin disk diffusion test on more than 3200 nonfastidious isolates supported the FDA-approved zone size interpretive criteria when the MIC breakpoint of < or = 2.0 micrograms/mL is used to define the trovafloxacin-susceptible category.

Zentralbl Bakteriol, 1998 Dec, 288(4), 509 - 18
Comparative in-vitro activities of trovafloxacin, ciproflaxacin, ofloxacin, and broad-spectrum beta-lactams against aerobe blood culture isolates; Seifert H; The in vitro activity of trovafloxacin, a new fluoroquinolone, was compared with that of ciprofloxacin, ofloxacin, fleroxacin, ceftazidime, piperacillin/tazobactam, and meropenem against 613 consecutively recovered blood isolates from recently hospitalized patients . Susceptibility testing was performed by agar dilution according to NCCLS guidelines . Test strains included Acinetobacter species (n = 26), Escherichia coli (n = 137), Enterobacter species (n = 27), Klebsiella species (n = 42), Proteus species (n = 16), Pseudomonas aeruginosa (n = 28), Serratia marcescens (n = 13), Stenotrophomonas maltophilia (n = 7), enterococci (n = 54), coagulase-negative staphylococci (n = 38), Staphylococcus aureus (n = 137), Streptococcus pneumoniae (n = 27), beta-haemolytic streptococci (n = 13), and viridans group streptococci (n = 48) . The overall respective MICs at which 50% and 90% of isolates were inhibited (MIC50s and MIC90s) were as follows: trovafloxacin, 0.06 and 1 mg/l; ciprofloxacin, 0.25 and 4 mg/l; ofloxacin, 0.5 and 4 mg/l; fleroxacin, 0.5 and 16 mg/l; ceftazidime, 2 and 128 mg/l; piperacillin/tazobactam, 2 and 8 mg/l; meropenem, 0.06 and 4 mg/l . For the quinolones, the rank order of activity against gram-negative microorganisms was ciprofloxacin > trovafloxacin > ofloxacin = fleroxacin, against gram-positive organisms, trovafloxacin > ciprofloxacin = ofloxacin > fleroxacin . Data obtained showed the similar activity of trovafloxacin and ciprofloxacin against gram-negative pathogens and the superior activity of trovafloxacin against gram-positive bacteria thus making it a potential candidate for the empiric treatment of patients with suspected bacteremia and sepsis.

Pharmazie, 1999 Jan, 54(1), 70 - 2
In vitro effect of imipenem on Acinetobacter baumannii; Hostacka A; Imipenem at suprainhibitory concentrations (2x, 4x or 8x MIC) induced postantibiotic effects (PAEs) (suppression of bacterial growth after a short time exposure of bacteria to antimicrobials) against two of three Acinetobacter baumannii strains . The highest concentration tested demonstrated the longest delay of bacterial regrowth (1.7 h (strain 5570) or 3.9 h (strain 6070)) . All . A . baumannii strains showed changes in surface hydrophobicity and serum sensitivity after treatment with imipenem . The antibiotic at 8x MIC reduced hydrophobicity of the strains most significantly (from 42.3%-72.0%) as compared to controls (without antibiotic) . Susceptibility of the treated bacteria to serum bactericidal activity has also been lowered . Though imipenem suppressed bacterial growth and decreased surface hydrophobicity of the bacteria, it increased survival of bacteria after incubation with serum . These different alterations observed in the studied strains should be taken into account when evaluating the effects of imipenem.

J Clin Microbiol, 1999 Mar, 37(3), 758 - 61
Spread of amikacin resistance in Acinetobacter baumannii strains isolated in Spain due to an epidemic strain; Vila J et al.; Sixteen amikacin-resistant clinical Acinetobacter baumannii isolates from nine different hospitals in Spain were investigated to determine whether the high incidence of amikacin-resistant A . baumannii was due to the dissemination of an amikacin-resistant strain or to the spread of an amikacin resistance gene . The epidemiological relationship studied by repetitive extragenic palindromic PCR and low-frequency restriction analysis of chromosomal DNA showed that the same clone was isolated in eight of nine hospitals, although other clones were also found . The strains were studied for the presence of the aph(3')-VIa and aac(6')-I genes, which encode enzymes which inactivate amikacin, by PCR . All 16 clinical isolates had positive PCRs with primers specific for the amplification of the aph(3')-VIa gene, whereas none had a positive reaction for the amplification of the aac(6')-I gene . Therefore, the high incidence of amikacin resistance among clinical A . baumannii isolates in Spain was mainly due to an epidemic strain, although the spread of the aph(3')-VI gene cannot be ruled out.

Med Oncol, 1998 Dec, 15(4), 270 - 4
Outbreak of nosocomial Acinetobacter baumannii bacteremia in a high risk ward; Kapil A et al.; Acinetobacter baumannii is emerging as a major cause of nosocomial infections particularly in high risk patients . Being resistant to adverse environmental conditions, it can stay for prolonged periods in the hospital environment . We report an outbreak in the medical oncology ward where nine patients suspected of bacteraemia were blood culture positive for A . baumannii from the two samples each, one collected through the i.v . cannula and another through the peripheral veneous puncture . The bacteria was also isolated from the environmental sources from the various samples collected . The biotype, antibiogram, cellular protein profiles on SDS-PAGE and the restriction enzyme analysis patterns of the patient isolates and the environmental isolates were similar . This points to the environment as a source of infection . With reinforcement of proper barrier nursing and use of disposable heparine ampoules it was possible to control the outbreak.

Diagn Microbiol Infect Dis, 1998 Dec, 32(4), 289 - 301
Antimicrobial susceptibility patterns for pathogens isolated from patients in Latin American medical centers with a diagnosis of pneumonia: analysis of results from the SENTRY Antimicrobial Surveillance Program (1997) . SENTRY Latin America Study Group; Sader HS et al.; Pneumonia is the most common fatal hospital-acquired infection, with attributable mortality rates ranging from 30 to 60% . Rapid initiation of optimal antimicrobial therapy is essential for obtaining treatment success . In this report the antimicrobial susceptibility of 556 strains from the lower respiratory tract were collected by the SENTRY Antimicrobial Surveillance Program (1997) . These strains were isolated from hospitalized patients with pneumonia in 10 Latin American centers (6 countries) as part of this 68-center worldwide program . The isolates were susceptibility tested against more than 70 drugs (35 reported) by the reference broth microdilution method . Klebsiella pneumoniae and Escherichia coli phenotypically consistent with extended spectrum beta-lactamase (ESBL) production were characterized further by ribotyping and pulsed-field gel electrophoresis . The five most frequently isolated species were (n/%): Pseudomonas aeruginosa (149/26.8%), Staphylococcus aureus (127/22.8%), Acinetobacter spp . (66/11.9%), Klebsiella spp . (56/10.1%), and Enterobacter spp . (40/7.2%) . P . aeruginosa demonstrated high rates of resistance to a majority of the antimicrobial drugs tested . Carbapenems, amikacin, and piperacillin/tazobactam demonstrated the highest susceptibility rates (73.8-77.2%) against P . aeruginosa, however the lowest resistance rate was observed for cefepime (6.7%) . Acinetobacter spp . also showed very high rates of resistance and the most active compounds were imipenem and meropenem (89.0% susceptibility) followed by the tetracyclines . Cephalosporin susceptibilities among Klebsiella spp . were low: cefoxitin, 73.0%; ceftazidime, 69.4%; and ceftriaxone, 65.9% . Approximately 37% and 28% of K . pneumoniae and E . coli isolates, respectively, were considered ESBL producers based on NCCLS criteria . Ceftriaxone was active against only 52.5% of Enterobacter spp . isolates, whereas cefepime was active against 90.0% of isolates (MIC50, < or = 0.12 microgram/mL) . Oxacillin resistance was detected in nearly 50% of S . aureus isolates . The most active drugs against S . aureus were vancomycin, teicoplanin, and quinupristin/dalfopristin (MIC90, 1 microgram/mL) . In summary, our study of pneumonias in Latin American medical centers demonstrated a greatly increased prevalence of Acinetobacter spp . and higher resistance rates among Gram-negative bacilli when compared with similar controlled studies from North America.

FEMS Microbiol Lett, 1999 Jan 15, 170(2), 413 - 8
Cloning and complete nucleotide sequence of Acinetobacter radioresistens CMC-1 AglyA gene encoding serine hydroxymethyltransferase; Hong MC et al.; A gene (AglyA) encoding serine hydroxymethyltransferase of Acinetobacter radioresistens CMC-1 was cloned and sequenced . Nucleotide sequence analysis of AglyA predicted a single open reading frame (ORF) of 1251 bp encoding a 417-amino acid polypeptide . Two putative MetR-like binding sites (5'-TGAAACATGAGCT) and (5'-TGAGCAAAGTTCA), centered at bp -123 and -95 relative to the +1 translation start site were found, which have six out of nine and eight out of nine nucleotides that match to the consensus sequence of Escherichia coli (5'-TGAANNT/ANNTTCA), respectively . The enzyme also showed a high level of homology to other sources of serine hydroxymethyltransferase proteins.

FEBS Lett, 1999 Jan 22, 443(1), 57 - 60
Purification and characterization of a major 40 kDa outer membrane protein of Acinetobacter baumannii; Jyothisri K et al.; Acinetobacter baumannii, an opportunistic pathogen, is well known to cause a wide spectrum of nosocomial infections particularly in intensive care units . The major outer membrane (OM) protein, OmpAb, of 40 kDa from A . baumannii has been identified and purified to homogeneity from cultures grown at 30 degrees C and 100 mM NaCl . The synthesis of OM proteins of A . baumannii is thermoregulated and osmoregulated . The pore forming ability of the purified OmpAb and the diffusion of uncharged solutes in proteoliposomes has been demonstrated by following the liposomal swelling assay . The trimeric OmpAb is characterized as a porin with a pore size of 1.3 nm and is found to be similar to the OmpF of Escherichia coli and can possibly be classified as a general diffusion pore . It appears that OmpAb plays an important role in the diffusion properties of the outer membrane of A . baumannii.

Nucleic Acids Res, 1999 Feb 15, 27(4), 1056 - 62
Random mutagenesis by recombinational capture of PCR products in Bacillus subtilis and Acinetobacter calcoaceticus; Melnikov A et al.; We describe a general method for random mutagenesis of cloned genes by error-prone PCR or DNA shuffling that eliminates the need for post-amplification subcloning following each cycle of mutagenesis . This method exploits the highly efficient and recombinogenic nature of DNA uptake during natural transformation in the Gram-positive bacterium Bacillus subtilis and the Gram-negative bacterium Acinetobacter calcoaceticus . Plasmid systems were designed that allow capture of PCR-amplified DNA fragments by marker-replacement recombination with a structurally similar helper plasmid resident in the transformation recipient . This recombination event simultaneously transfers the amplified sequences into the helper plasmid and restores the integrity of a drug resistance gene, thereby affording a direct selection for fragment capture . Although this strategy was sufficiently effective to permit recovery in B . subtilis of up to 10(3) transformants/microgram of PCR product, equivalent plasmid systems were approximately 100 times more efficient in A.calcoaceticus . Acinetobacter calcoaceticus also offers the advantage of essentially constitutive transformation competence in ordinary complex broth, such as LB, in contrast to two-step growth in semi-synthetic media required for optimal transformation of B.subtilis.

Appl Environ Microbiol, 1999 Feb, 65(2), 802 - 6
Characterization of two novel propachlor degradation pathways in two species of soil bacteria; Martin M et al.; Propachlor (2-chloro-N-isopropylacetanilide) is an acetamide herbicide used in preemergence . In this study, we isolated and characterized a soil bacterium, Acinetobacter strain BEM2, that was able to utilize this herbicide as the sole and limiting carbon source . Identification of the intermediates of propachlor degradation by this strain and characterization of new metabolites in the degradation of propachlor by a previously reported strain of Pseudomonas (PEM1) support two different propachlor degradation pathways . Washed-cell suspensions of strain PEM1 with propachlor accumulated N-isopropylacetanilide, acetanilide, acetamide, and catechol . Pseudomonas strain PEM1 grew on propachlor with a generation time of 3.4 h and a Ks of 0.17 +/- 0.04 mM . Acinetobacter strain BEM2 grew on propachlor with a generation time of 3.1 h and a Ks of 0.3 +/- 0.07 mM . Incubations with strain BEM2 resulted in accumulation of N-isopropylacetanilide, N-isopropylaniline, isopropylamine, and catechol . Both degradative pathways were inducible, and the principal product of the carbon atoms in the propachlor ring was carbon dioxide . These results and biodegradation experiments with the identified metabolites indicate that metabolism of propachlor by Pseudomonas sp . strain PEM1 proceeds through a different pathway from metabolism by Acinetobacter sp . strain BEM2.

Rev Med Chil, 1998 Sep, 126(9), 1079 - 84
{Surface characteristics and antimicrobial sensitivity of clinical strains of Acinetobacter spp}; Martinez MA et al.; BACKGROUND: The treatment of nosocomial infections caused by Acinetobacter baumannii has been hindered by the easiness of this species to acquire antimicrobial resistance . AIM: To study surface hydrophobicity, the presence of capsule and antimicrobial susceptibility of nosocomial Acinetobacter spp strains . MATERIAL AND METHODS: Ninety four Acinetobacter spp strains isolated from a public hospital of Santiago, between July 1995 and April 1996, were studied . RESULTS: Compared to Acinetobacter genospecies 3 isolates, A baumannii isolates exhibited greater antimicrobial resistance, was uniformly susceptible to imipenem and highly resistant to other antimicrobials of clinical use . Most strains of biotypes 8 and 9 were hydrophilic and encapsulated, whereas those of infrequent biotypes and of Acinetobacter genospecies 3 were, with few exceptions, hydrophobic and not encapsulated . CONCLUSIONS: Capsule production might confer a greater virulence to Acinetobacter baumannii biotypes 8 and 9, and explain their higher prevalence in the studied hospital.

Srp Arh Celok Lek, 1998 Nov-Dec, 126(11-12), 423 - 9
{Antibiotic sensitivity of bacteria isolated from the urine of children with urinary tract infections from 1986 to 1995}; Lazarevic G et al.; In adults and in children urinary system infections are mostly caused by gram-negative and rarely by gram-positive bacteria . Of gram-negative bacteria the most frequent cause of infections are Escherichia coli, Klebsiella species, Proteus mirabilis, Pseudomonas aeruginosa, Acinetobacter, Serratia etc., and of gram-positive bacteria Enterococcus, Staphylococcus, Streptococcus agalactiae . In rare cases the cause of infection may also be Pneumococcus and Haemophilus influenzae . AIM OF THE STUDY: The aim of the study was to investigate the sensitivity to antibiotics of gram-negative bacteria as the predominant cause of urinary infections . METHOD OF THE STUDY: We isolated 20,615 bacterium species from urine of children hospitalized or treated as outpatients at the University Children's Hospital in Belgrade . Urine was collected classically, i.e . by taking the second clean stream into a sterile test tube or by Uricult test . The samples were cultured on blood plates and endo-agar . Identification was done by standard bacteriologic methods and when findings were dubious API-20E (bioMerieux) was used . Bacterium sensitivity to nine antibiotics (ampicillin, cephalexin, cefotaxime, chloramphenicol, gentamicin, amikacin, co-trimoxazole, nalidixic acid and nitrofurantoin) was assessed with disc diffuse method on Muller-Hinton agars . RESULTS: Based on the obtained results, Escherichia coli species sensitivity to amikacin, gentamicin, cefotaxime, nalidixic acid and nitrofurantoin ranged from 90 to 100%; sensitivity to co-trimoxazole and chloramphenicol ranged from 70 to 80%, to cephalexin from 50 to 60%, while to ampicillin it was only 20% . Klebsiella species sensitivity to nalidixic acid and cefotaxime was 70-85%; to amikacin, cefotaxime, co-trimoxazole and gentamicin 60-80%; to cephalexin and chloramphenicol 40-50%, and to ampicillin only 5-15% . Proteus species showed sensitivity to amikacin, gentamicin, cefotaxime and nalidixic acid of 90-95%; to co-trimoxazole and chloramphenicol 70-80%; to cephalexin and ampicillin 40-50%, and to nitrofurantoin 10% . Pseudomonas aeruginosa species showed the highest level of sensitivity to amikacin (40-50%), and somewhat lower to gentamicin (10-40%), and a very low sensitivity to other antimicrobial drugs (10-25%) . DISCUSSION: It may be noted from the above data that gram-negative bacteria are the cause of urinary infections in about 90% of cases, while gram-positive bacteria are the cause in only 10%, which is in accordance with data from literature . Of all antibiotic drugs ampicillin (a wide spectrum penicillin) had a very significant role in the therapy of urinary infections . However, the long-term usage of ampicillin led to increased resistance to the drug in infections caused by Escherichia coli . Natural resistance to ampicillin of Klebsiella species limited its usage when penicillin was first introduced . Proteus mirabilis species, especially those isolate in primary infection, are often sensitive to amino penicillin . Contrary to Proteus mirabilis, indole-positive Proteus and Providentie species show a high resistance to these antibiotics . Due to the crisis in our country and the lack of other antibiotics, ampicillin was widely used . The wide use of the drug caused evident resistance of Escherichia coli and Proteus mirabilis to this antibiotic . A fall in the sensitivity of Klebsiella to cephalexin, gentamicin, amikacin and co-timoxazole, which occurred in 1992, has been explained by intrahospital circulation of multiresistant Klebsiella species . The sensitivity of isolated gram-negative bacteria Escherichia coli, Klebsiella species, Proteus mirabilis and Pseudomonas aeruginosa was the most prominent to aminoglycosides (amikacin and gentamicin) . The most frequent mechanism of enterobacterial resistance to trimethoprim and co-trimoxazole involves dihydrofolate reductase enzyme . Comparative studies related to the administration of co-trimoxazole have shown that the difference in the efficacy between thes

Bratisl Lek Listy, 1998 Nov, 99(11), 573 - 8
{Occurrence of gram-negative non-fermenting rods in hemocultures and their sensitivity to antimicrobial agents}; Hejnar P et al.; In the period from January 1993 to June 1996 were at the Department of Microbiology of the University Hospital in Olomouc 122 strains of Gram-negative nonfermentative rod-shaped bacteria isolated from haemocultures . The majority represented the group of 51 strains of the genus Acinetobacter (41.8%), complex A . calcoaceticus-baumannii (Acb complex) . The second largest group were 21 strains (17.2%) of Pseudomonas aeruginosa . These were followed by 17 strains (13.9%) of Stenotrophomonas maltophilia, 8 strains (6.6%) of non-Acb complex acinetobacters, 6 strains (4.9%) of Pseudomonas putida and 5 strains (4.1%) of Alcaligenes xylosoxidans . The remaining species were represented only by 1-2 strains . In three isolations was the identification impossible . The majority of strains (24.6%) were from the Department of Haematology of the University Hospital in Olomouc . The most frequent diagnoses in patients with positive haemocultures were leukemias and lymphomas (24.6%) . The most effective tested antimicrobial agents were ceftazidime (93.4% of sensitive strains) and ofloxacin (91.7%) . From the total number of 80 strains detected using the equipment BacT/Alert 120, 22 (27.5%) were isolated repeatedly confirming their role in the etiology of bacteriemic or septic episodes . Because only one blood sample was obtained in 34 cases (58.6%) of the remaining 58 only once detected strains, it was impossible to confirm their etiologic role by repeated isolation . (Tab . 6, Ref . 22.)

FEMS Microbiol Lett, 1999 Jan 1, 170(1), 199 - 209
Characterization of the Acinetobacter baumannii Fur regulator: cloning and sequencing of the fur homolog gene; Daniel C et al.; Growth kinetics, siderophore activity and iron-regulated bacterial proteins of Acinetobacter baumannii BM2580 were studied in iron-restricted and iron-supplemented chemically defined media . Iron-regulated outer membrane proteins of 75 kDa and 80 kDa were expressed under iron-restricted conditions . Cloning and sequencing of the complete iron-uptake regulatory (fur) gene from A . baumannii BM2580 is reported for the first time . This gene is preceded by a single autoregulated promoter whose -10 region overlaps the Fur binding site . The open reading frame identified encodes a polypeptide consisting of 145 amino acids . The fur gene is followed by a divergent open reading frame coding for the C-terminus of a putative PilU protein . Sequence analysis indicates that the Fur protein of A . baumannii was 63% identical to the Escherichia coli Fur protein.

Arch Microbiol, 1999 Jan, 171(2), 73 - 80
A sensitive, viable-colony staining method using Nile red for direct screening of bacteria that accumulate polyhydroxyalkanoic acids and other lipid storage compounds; Spiekermann P et al.; The oxazine dye Nile blue A and its fluorescent oxazone form, Nile red, were used to develop a simple and highly sensitive staining method to detect poly(3-hydroxybutyric acid) and other polyhydroxyalkanoic acids (PHAs) directly in growing bacterial colonies . In contrast to previously described methods, these dyes were directly included in the medium at concentrations of only 0.5 microgram/ml, and growth of the cells occurred in the presence of the dyes . This allowed an estimation of the presence of PHAs in viable colonies at any time during the growth experiment and a powerful discrimination between PHA-negative and PHA-positive strains . The presence of Nile red or Nile blue A did not affect growth of the bacteria . This viable-colony staining method was in particular applicable to gram-negative bacteria such as Azotobacter vinelandii, Escherichia coli, Pseudomonas putida, and Ralstonia eutropha . It was less suitable for discriminating between PHA-negative and PHA-positive strains of gram-positive bacteria such as Bacillus megaterium or Rhodococcus ruber, but it could also be used to discriminate between wax-ester- and triacylglycerol-negative and -positive strains of Acinetobacter calcoaceticus or Rhodococcus opacus . The potential of this new method and its application to further investigations of PHA synthases and PHA biosynthesis pathways are discussed.

Br J Dermatol, 1998 Nov, 139(5), 885 - 8
Cellulitis due to Escherichia coli in three immunocompromised subjects; Yoon TY et al.; In adults, cellulitis is usually caused by group A streptococci and Staphylococcus aureus . However, in patients with underlying disease, it may be caused by other organisms, such as Acinetobacter, Clostridium septicum, Enterobacter, Haemophilus influenzae, Proteus mirabilis or Escherichia coli . We report three cases of cellulitis of the lower legs where E . coli was the causative bacterial organism . It is important to suspect E . coli as a causative organism if blistering cellulitis occurs, especially in patients with underlying diseases.

JAMA, 1999 Jan 6, 281(1), 67 - 71
Antibiotic susceptibility among aerobic gram-negative bacilli in intensive care units in 5 European countries . French and Portuguese ICU Study Groups; Hanberger H et al.; CONTEXT: Surveillance of antibiotic resistance is especially important in intensive care units (ICUs) because the infection rates are much higher there than in other hospital wards and most epidemics with multiresistant bacteria originate in ICUs . OBJECTIVE: To evaluate the incidence of decreased antibiotic susceptibility among aerobic gram-negative bacilli isolated from patients in ICUs . DESIGN: Consecutive specimens collected on clinical indications from ICU patients were cultured and tested . Minimum inhibitory concentrations for amikacin, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, piperacillin, and piperacillin-tazobactam were determined using E test . SETTING: Eighteen hospitals in Belgium, 40 in France, 20 in Portugal, 30 in Spain, and 10 in Sweden . SUBJECTS: A total of 9166 gram-negative strains were initially isolated from 7308 patients between June 1994 and June 1995 . MAIN OUTCOME MEASURES: The incidence of decreased susceptibility, defined as the sum of resistant and intermediate categories with use of the minimum inhibitory concentration break points recommended by the National Committee for Clinical Laboratory Standards . RESULTS: The most frequently isolated organisms were Enterobacteriaceae (59%) followed by Pseudomonas aeruginosa (24%) . The main sources were respiratory tract (42%), urine (26%), blood (14%), abdomen (11%), and skin and soft tissue (7%) . Decreased antibiotic susceptibility across all species and drugs was highest in Portuguese ICUs followed by French, Spanish, Belgian, and Swedish ICUs . The highest incidence of resistance was seen in all countries among P aeruginosa (up to 37% resistant to ciprofloxacin in Portuguese ICUs and 46% resistant to gentamicin in French ICUs), Enterobacter species, Acinetobacter species, and Stenotrophomonas maltophilia, and in Portugal and France among Klebsiella species . CONCLUSION: The high incidence of reduced antibiotic susceptibility among gram-negative bacteria in these ICUs suggests that more effective strategies are needed to control the selection and spread of resistant organisms.

Microbios, 1998, 95(380), 45 - 53
Adherence of Acinetobacter baumannii to rat bladder tissue; Sepulveda M et al.; Acinetobacter baumannii, an important nosocomial pathogen, causes severe infections in patients of intensive care units, but its pathogenic attributes are unknown . Previously, the adherence of A . baumannii to cell lines has been negative in the authors' laboratory . In this work, the adherence of strains of A . baumannii of various biotypes to small pieces of rat bladder tissue was investigated . Tissue pieces were submerged into cultures of A . baumannii and sessile cells were counted after removing planktonic bacteria . Fimbriae and sessile cells were examined by transmission and scanning electron microscopy, respectively . In contrast to a uropathogenic strain of Escherichia coli, all cultures exhibited a mannose- and galactose-resistant agglutination of human group O red blood cells as well as mannose- and galactose-resistant adherence to the bladder tissue . Inhibition of exopolysaccharide synthesis did not modify adherence . Indeed, adherence, apparently unrelated to these fimbriae or to the exopolysaccharide, may be a factor contributing to the pathogenicity of A . baumannii in the urinary tract or in other tissues.

J Med Microbiol, 1998 May, 47(5), 455 - 62
Molecular epidemiology of aminoglycoside resistance in Acinetobacter spp; Seward RJ et al.; Most aminoglycoside resistance in Acinetobacter spp . involves production of aminoglycoside-modifying enzymes . Previous studies have shown that the genes encoding these enzymes can be present on plasmids, transposons or within integron-type structures . To determine whether particular mechanisms of aminoglycoside resistance have developed in strains from specific geographical locations (with subsequent clonal spread), or whether common mechanisms have been acquired by genotypically distinct clinical isolates of Acinetobacter spp . throughout the world, a genotypically heterogeneous collection of 24 multiresistant clinical isolates of Acinetobacter spp . from 15 hospitals in 11 countries worldwide was studied . All were resistant to two or more aminoglycoside antibiotics . The full aminoglycoside resistance profile was determined for each isolate, allowing a putative enzyme content to be inferred, with subsequent confirmation of enzyme content and genetic location by polymerase chain reaction (PCR) and hybridisation techniques . All produced at least one aminoglycoside-modifying enzyme, most commonly AAC(3)-I and ANT(3'')-I in various combinations . Other enzymes found were AAC(3)-II, AAC(6')-I, ANT(2''), APH(3')-I and APH(3')-VI . None was confined to strains from a particular geographical area . Nine isolates transferred resistance mediated by AAC(3)-I, ANT(2'')-I, APH(3')-I or APH(3)'-VI by conjugation to a sensitive strain of A . baumannii, but most resistance was non-transferable . PCR mapping revealed an integron location in six isolates for the aac(3)-Ia gene and in three isolates for the ant(3'')-Ia gene . Overall, the study demonstrated that similar aminoglycoside-modifying enzymes are found in unrelated isolates of Acinetobacter spp., and that particular genes are not restricted to specific areas of the world . The demonstration of certain genes on plasmids and integrons emphasises the probable importance of these structures in the dissemination of certain types of aminoglycoside resistance in Acinetobacter spp.

Presse Med, 1998 Dec, 27 Suppl 5, 47 - 50
{Nosocomial infections}; Joly-Guillou ML; WIDE-SPECTRUM beta-LACTAM PRODUCERS: A French survey demonstrated that Enterobacter aerogenes is currently the preferential host for this plasmid, apparently more so in general hospitals than in University hospitals . CANDIDEMIA: The highest rate of positive blood tests for candida was found in anti-cancer centers . VANCOMYCIN-RESISTANT STRAINS: Reduced susceptibility of methicillin-resistant staphylococci to vancomycin appears to be rather frequent (approximately 10% of strains isolated in one Japanese hospital) . It is important to recognize germ populations with a homogeneous or heterogeneous pattern of resistance . In addition, a Spanish survey demonstrated that a large number of inpatients or outpatients harbor vancomycin-resistant enterococci . THE ACINETOBACTER ISSUE: In order to limit the emergence of multiresistant strains and control epidemics, a strong prevention program must be associated with an adapted policy for antibiotic use.

Presse Med, 1998 Dec, 27 Suppl 5, 31 - 3
{Virulence and its relationship to antibiotic resistance}; Joly-Guillou ML; PATHOGENIC ISLANDS: Certain DNA blocks inserted into the chromosome of most Gram negative bacteria originated in pathogens found in plants . VIRULENCE-ANTIBIOTIC INTERACTIONS: During the invasive phase, the bacterial cell covers itself with adhesins which facilitate its adherence to tissues . The bacterial cell produces a fibronectin which protects its defense systems . Antibiotics favor bacterial resistance by increasing the expression of surface adhesins and fibronectin production . PENICILLIN RESISTANT PNEUMOCOCCI: Experimental models have demonstrated that mortality in mice and host resistance to pneumococcal infection are related to the type of capsule and not to antibiotic resistance . QUORUM SENSING: The bacterial inoculum regulates the production of virulence factors in vivo via quorum sensing . This regulation can play an important role in Pseudomonas aeruginosa infections . ACINETOBACTER BAUMANNI VIRULENCE: Long poorly understood, factors favoring A . baumanni virulence appear to result from bacterial production of IROMPs in the extracellular growth medium in response to iron depletion during the exponential growth phase.

Chemotherapy, 1999 Jan-Feb, 45(1), 22 - 7
In vitro activity of trovafloxacin (CP 99,219), a new fluoroquinolone against hospital isolates; Ling TK et al.; The susceptibility of 492 Enterobacteriaceae, 227 other gram-negative bacteria, 448 gram-positive bacteria and 108 anaerobic organisms was determined by the agar dilution method against trovafloxacin and other antibiotics . Trovafloxacin was highly active against most of the Enterobacteriaceae including Enterobacter spp . and Citrobacter spp . {minimum inhibitory concentration (MIC)90 <1 mg/l}, Acinetobacter spp . and Pseudomonas aeruginosa (MIC90 = 0.25 and 2 mg/l, respectively) . The antimicrobial activity was extended to the gram-positive bacteria including streptococci, Streptococcus pneumoniae, coagulase-negative staphylococci and methicillin-sensitive Staphylococcus aureus with MIC90 <1 mg/l . Enterococci and methicillin-resistant S . aureus were inhibited (MIC90 = 2 mg/l; sparfloxacin and ciprofloxacin were 16 and 64 mg/l, respectively) . Almost all anaerobic organisms were inhibited by trovafloxacin (MIC90 = 1 mg/l).

Arch Pharm Res, 1998 Jun, 21(3), 310 - 4
Resistance mechanism of Acinetobacter spp . strains resistant to DW-116, a new quinolone; Choi KH et al.; DW-116 is a new fluoroquinolone antimicrobial agent with a broad spectrum . In order to elucidate the resistance mechanism to DW-116 in Acinetobacter spp . bacteria, total chromosomal DNA was isolated from 10 strains of Acinetobacter spp . resistant to DW-116 . Quinolone resistance determinant region (QRDR) of DNA gyrase gene was amplified by PCR . The 345 bp nucleotide fragment yielded was inserted into pKF 3 which was used as the vector . Comparisons of the DNA sequences of 8 strains with that of the wild type strain revealed a Ser-83 to Leu mutation in mutants and all ten strains contained one silent mutation(T-->G) in QRDR . From Acinetobacter MB4-8 strain, DNA gyrase was isolated and purified, through no-vobiocin-sepharose, heparin-sepharose affinity column chromatography . The enzyme was composed of two subunits and the molecular mass of subunits A and B were 75.6 and 51.9 kDa, respectively . The supercoiling activity of the reconstituted DNA gyrase composed of subunit A from Acinetobacter MB4-8 and subunit B from E . coli was not inhibited by 128 micrograms/ml of ciprofloxacin . It might be said that one of the resistance mechanisms to DW-116 in A-cinetobacter MB4-8 was subunit A alteration of DNA gyrase.

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